POSTMORTEM IMAGING INTERPRETATION GUIDELINE 2015 IN JAPAN

Editor:Japan Radiological Society
andStudy Group of Japan Health and Labor Sciences Research

2015 Guideline for Postmortem Image Interpretation
Ver. 2015“Research for Implementation of Postmortem Imaging of Deaths Outside Medical
Institutions”
Edited by
Scientific Research Group, Ministry of Health, Labour and Welfare, Japan
Radiological Society
Japanese 2015 ver. Published by
KANEHARA & Co., LTD. (Tokyo)

Japanese edition
Chairpersons
Naoya Takahashi

Dep. Radiological Technology, Niigata University

Eiji Oguma

Dep. Radiology, Saitama Prefectural Children Hospital

Vice-chairperson
Hideki Hyodoh

Center for Cause of Death Investigation
Faculty of Medicine Hokkaido University

Committee and cooperator:
Yutaka Imai

Dep. Radiology, Tokai University

Noriaki Ikeda

Dep. Legal Medicine, Kyushu University

Satoshi Watanabe

Dep. Legal Medicine, Sapporo Medical University

Satoshi Hirasawa

Dep. Radiology, Gunma University

Morio Iino

Dep. Legal Medicine, Tottori University

Masanori Ishida

Dep. Radiology, Sanraku Hospital

Kensuke Ito

Dep. Emergency, Kameda Medical Center

Yohsuke Makino

Dep. Forensic Medicine, The University of Tokyo

Tomonori Murakami

Dep. Radiology, Naagsaki University

Hideyuki Nushida

Dep. Legal Medicine, Hyogo College of Medical

Minako Sakamoto

Dep. Emergency, Kyorin University

Yasuo Shichinohe

Dep. Emergency, Hokkaido Medical Center

Seiji Shiotani

Dep. Radiology, Seire Fuji Hospital

Seiji Yamamoto

Director, Ai Information Center

English version
Editor in Chief
H.HyodohCenter for cause of death investigation

Hokkaido University

Editor
N.IkedaLegal medicine

Kyushu University

Y.ImaiRadiology

Tokai University

N.Takahashi

Graduate School of Health Sciences
Niigata University

E.OgumaRadiology

Saitama Prefectural Children Hospital

S.Watanabe

Legal medicine

Sapporo Medical University

Japanese & English version translation committee
W.GonoiRadiology

The University of Tokyo

S.Hirasawa

Radiology

Gunma University

M.IinoLegal medicine

Tottori University

M.Ishida

Radiology

The University of Tokyo

N.Ito

Emergency Medicine

Kameda Medical Center

Y.Makino

Forensic medicine

The University of Tokyo

K.Matoba

Legal medicine

Hokkaido University

T.Murakami

Radiology

Nagasaki University

H.Nushida

Legal medicine

Hyogo College of Medical

H.OkumaRadiology

The University of Tokyo

N.Sakamoto

Legal medicine

Kyorin University

S.ShiotaniRadiology

Seirei Fuji Hospital

Y.Shichinohe

Emergency Medicine

Hokkaido Medical Center

G.Shirota

Radiology

The University of Tokyo

S.Yamamoto

Radiology

Ai Center

M.Yoshida

Legal medicine

Chiba University

Introduction
In Japan, a law to promote investigation of causes of death, the so called “Promotionof investigation of causes of death” law, was adopted at the Cabinet meeting in June,
2014. Under this law, the necessity to utilize postmortem imaging and scientificinvestigations to investigate the causes of death related to drugs and toxic
substances is stressed. However, as postmortem imaging must be performed with athorough understanding of all relevant issues including postmortem changes,
different from a diagnosis with images of the living patients, the Ministry of Health,Labour and Welfare (MHLW) requested relevant academic conferences and theJapan Medical Association to organize workshop seminars.
The guideline here was developed as a part of the MHLW Grant-in-Aid for Scientific
Research project, “Research for Implementation of Postmortem Imaging of Deaths
Outside Medical Institutions” led by the principal investigator, Hideki Hyodoh,
Sapporo Medical University, in collaboration with the Japan Radiological Society,
the Japanese Society of Legal Medicine, and the Japan Society of Autopsy Imaging.
The guideline contained in this volume is designed to provide guidelines forphysicians who will keep it at hand when interpreting postmortem images.
Postmortem imaging is greatly influenced by a number of conditions including
postmortem interval, as well as the temperature and humidity of the place where
the body has been kept. Further, it is also known that diagnostic accuracy varies
depending on whether the cause of death is endogenous or exogenous. Here, somepathologists say that only autopsies are needed to investigate causes of death.
However, postmortem imaging and autopsy are mutually supplementary, and a
precise investigation of causes of death by autopsy also requires postmortem images.
Postmortem imaging is currently performed with only CT with exceptions at somefacilities in Japan, but it is known that the precision of the postmortem imaging will
be improved with the use of MRI. For the convenience of readers, this guideline
contains some discussion and details of ways to improve the diagnostic accuracy by
MRI.
In the future, the necessity for guidelines to support postmortem image
interpretation will increase as investigations of causes of death become morecommonly implemented nationwide in Japan under the newly implemented law. In
creating this first version of the guideline, I expect to incorporate a broad range of
opinions of physicians involved in postmortem imaging by listening to publicly
provided comments, mainly from members of the relevant academic societies. I
sincerely wish that postmortem imaging will come to play an important role in thedeath investigation system in Japan together with the presently determined
autopsy findings, and that the findings will be utilized to protect the lives of thecitizens of Japan.
Yutaka Imai
Director of the Japan Radiological Society
Dean of Tokai University School of Medicine, Professor of Course of Specialized
Clinical Science, Department of Radiology, Tokai University School of Medicine

Note for the Compilation of the 2015 Guideline for Postmortem Image
Interpretation
The development of this guideline was initiated as a part of the MHLW
Grant-in-Aid for Scientific Research project in 2012 (MHLW Scientific Research
Program), titled “Research for Implementation of Postmortem Imaging of Deaths
Outside Medical Institutions”. The project was led by the principal investigator,
Hideki Hyodoh, Sapporo Medical University, in collaboration with the Japan
Radiological Society, the Japanese Society of Legal Medicine, and the Japan Societyof Autopsy Imaging. The project was continued as a part of the MHLW Grant-in-Aid
for Scientific Research project in 2013 (Research Program to Promote the Basic
Development of Community Medicine) led by the same principal investigator.

Weelaborated and proofread the manuscript with members of the development teamand editing committee, expecting this guideline to play the role as a forerunner inthe framework of investigating causes of death, as well as to serve as a standard forphysicians and professionals involved in postmortem imaging. We heard thatphysicians in Japan engaged in the interpretation of the postmortem images
experienced difficulties in interpreting images, and we decided to publish the
Guideline for Postmortem Image Interpretation (Ver. 0) in March 2012, although atthat point it was incomplete. We have then solicited comments made public throughthe Japan Radiological Society and the Japanese Society of Legal Medicine, andmade modification incorporating these proposals, and have now decided to present
this updated guideline (ver. 2015).
Postmortem images are also called autopsy imaging (Ai) in Japan as suggested by apreviously involved practitioner. This guideline is mainly designed for postmortem
imaging of corpses who died outside hospitals, and where some period of time has
elapsed after death, unlike the case of in-hospital deaths. Therefore, we used theterm, “postmortem images”, consistently throughout. I have emphasize that using
this guideline for deaths in hospitals may lead to mistaken evaluations anddeterminations since deaths in hospital or clinics are not covered by this guideline.
Please use it carefully on your own responsibility.
Finally, I wish to express my gratitude to members of the guideline developing
committee for investing the very large amounts of time they have readily provided,
and to Miss. Haruna Sakurai for the invaluable work in proofreading the drafts, ina busy daily schedule with routine practice, paper work, research, and educational
activities.

March, 2015
Hideki Hyodoh
Specially appointed lecturer, Department of Legal Medicine, Sapporo Medical
University
Principal Investigator of “Research for Implementation of Postmortem Imaging of
Deaths Outside Medical Institutions”, the MHLW Grant-in-Aid for Scientific
Research projectAt the Publication of the 2015 Guideline for Postmortem Image Interpretation
This “Guideline for Postmortem Image Interpretation” was developed as a part of
the MHLW Grant-in-Aid for Scientific Research project, titled “Research for
Implementation of Postmortem Imaging of Deaths Outside Medical Institutions”(Principal investigator, Hideki Hyodoh, Sapporo Medical University).
We requested physicians who have played an active role in radiology, emergency
medicine, and forensic medicine using postmortem images to join the guideline
developing committee.
The guideline is a document systematically created to support interpreters of
medical images in all fields in order to be able to make appropriate evaluations insituations where postmortem image interpretation is required. Guidelines are only
guidelines, and do not consider all matters that must be complied with under all
circumstances. This implies that just following the letter of the guidelines will notlead to better determinations and evaluations. Further, even if a specific finding isapparently based on evidence, care must be shown in the interpretation, andindependent judgment is necessary to reach a correct interpretation.
This guideline is the first edition, and there will be points where improvements inspecific items and particulars are in order. I wish for physicians who use thisguideline in the field of forensic medicine as a reference for evaluations anddeterminations to actively provide opinions to improve the guideline together withus.
March, 2015
Noriaki Ikeda
Japanese Society of Legal Medicine
Professor of Department of Forensic Pathology and Sciences, Graduate School of
Medical Sciences, Kyushu University

Background to the Development of the Guideline, and Rules and Procedures for its
Use
The development of this guideline was initiated as a part of the MHLW
Grant-in-Aid for Scientific Research project in 2012 (MHLW Scientific Research
Program), titled “Research for Implementation of Postmortem Imaging of Deaths
Outside Medical Institutions”. The project was led by the principal investigator,
Hideki Hyodoh, Sapporo Medical University, in collaboration with the Japan
Radiological Society, the Japanese Society of Forensic Medicine, and the Japan
Society of Autopsy Imaging. The project was continued as a part of the MHLW
Grant-in-Aid for Scientific Research project in 2013 (Research Program to Promote
the Basic Development of Community Medicine) led by the same principal
investigator.
This guideline for postmortem image interpretation is prepared for physicians
engaged in postmortem imaging and interpretation of postmortem images. The
guideline development committee searched through and analyzed the literatureusing the latest databases, and structured abstracts. Based on this analysis, thecommittee created clinical questions (CQ), for matters which will present problems
in actual interpretations. Detailed answers are provided for each CQ with objective
data as far as that is possible, and recommended grades of the findings are alsodetailed. In assigning a recommended grade, we took the role of postmortem images
into consideration by arranging them into “State evaluations” and “Cause of death
identification” items. We also indicated the characteristic background to theparticular state, and the characteristic findings to be expected from the images, aswell as for the disease conditions, illnesses, and other particulars to pay attention toin the evaluation by adding detailed explanations to each CQ. For the references,
we have indicated the search formulas, and also presented whatever documents theguideline developing committee considered to be of assistance. Further, additions by
the committee are indicated with an asterisk (*) at the end of a comment in therelevant CQ. We modified the draft version by referring to comments provided
publicly, and this completed the 2015 version.
The recommended grades of pediatric postmortem imaging (CQs 20-33) aredescribed as “Recommended Grade B”, when there is nothing that may beconsidered to impede the investigation / image interpretation, and where findings
from postmortem imaging may lead to the establishment of the cause of death.
Overall, we feel that this guideline is well structured as a guideline for pediatricpostmortem imaging with a full awareness of the efforts needed for the“Implementation of postmortem imaging (Ai) for all cases of child deaths” scheduled
to be introduced in Japan. It is anticipated that future versions will enable moredetailed elaborations as the findings from more cases are included. (PediatricPostmortem Imaging (CQs20-33) have deleted in English version.)
For a final note, please keep in mind that this guideline does not cover some items
required for interpretation of deaths in hospitals because it is designed for corpsesof persons who have died outside medical institutions. Therefore, if used for deaths
in medical institutions including hospitals and clinics, it should be used with care,and on the responsibility of the physicians who conduct the postmortem imaging.
When filling in inquest report forms, it is not possible to make a final determinationof whether a death is due to internal or external causes based on only findings of CT
images. If there are matters that remain unclear, it will be necessary to indicate“unknown” and recommend further detailed examination such as autopsy. Careful
evaluations by the practicing physicians are required and can be considered thebasic premise for the suggestions in the Guideline.

Evidence Levels and Recommended Grades (Method of searching the literature)
Method of searching the literature for the matters detailed in this guideline
1) Using the following search formulas, 181 papers were selected from PubMed on
August 7, 2013.
#1 Search (postmortem CT) or (postmortem computed tomography)#2 Search (causes of death) and (autopsy)#3 Search (#1) and (#2)
#4 Search (#3) and English〔Language〕Filters: published in the most recent 10
years2) Each committee member added secondary materials in addition to the papers
originally selected, and these are described in the relevant CQ.
For all papers, committee members in charge of a CQ prepared abstracts, and madeevaluations according to the evidence level of the papers classified by the scientificevidence.1)
Based on the results obtained with this procedure and referring to common, current
practices in Japan, we decided on the recommended grades according to theclassification method detailed in the table, and added these grades in the text when
considered necessary.
Evidence levels and recommended grades used in this guideline
Evidence level 1)
1. Systematic review / Meta-analysis
2. Based on one or more randomized controlled trials
3. Based on non-randomized controlled trials
4. Based on analytic epidemiological studies (cohort study and case-control study)
5. Based on descriptive research (case report or case series)
6. Comments from the committee and individual experts not based on patient data
Recommended Grades
A. Possible to diagnose reliably with postmortem images / Postmortem imaging
strongly recommended.

B. Postmortem images are very useful in the diagnosis. / Postmortem imaging
recommended.
C1. Postmortem images are useful in diagnosing. / Postmortem imaging may beconsidered, but scientific evidence will not be conclusive.
C2. Careful evaluation is necessary to distinguish the finding from other evidence. /Postmortem imaging not recommended due to lack of sufficient scientific evidence.
D. Difficult to diagnose. / Postmortem imaging not recommended.
References
1) Minds, Clinical Practice Guidelines Selection Committee (supervisor), Tsuguya
Fukui, Masahiro Yoshida, Naoto Yamaguchi (eds), (2007), Minds, 2007 Guidance fordeveloping clinical practice guidelines, Igaku-Shoin Ltd.

CQ table
CQ1

What are postmortem changes that can be visualized in postmortem
images?

CQ2

Are all high densities in the cranium hemorrhages?

CQ3

Can hypostasis and clotting in the heart or blood vessels be distinguishedfrom thrombosis by postmortem CT scans?

CQ4

What are useful findings to suggest deaths due to external causes inpostmortem images?

CQ5

Is it possible to exclude all deaths due to external causes by postmortem
imaging?

CQ 6

In postmortem radiography, what findings are useful to determine deathfrom natural causes?

CQ7

What are positive findings to diagnose injuries in postmortem imaging?

CQ8

Which postmortem image findings are useful for evaluating cervical spine
injuries?

CQ9

Can unenhanced postmortem CT scans help diagnose an acute coronary
syndrome as a cause of death?

CQ10

What are the best modalities for and acceptable findings to detect acutecoronary syndrome on postmortem images?

CQ11

Can postmortem CT scans be used to diagnose pericardial hematomas?

CQ12

Can postmortem CT scans detect subarachnoid hemorrhages as a cause ofdeath?

CQ13

Is it possible to diagnose cerebral hemorrhages which are causes of death?

CQ14

Can aortic aneurysms and aortic dissections be diagnosed as the cause ofdeath by postmortem imaging?

CQ15

What are useful findings of postmortem imaging in the diagnosis ofdrowning?

CQ16

What are useful findings to determine hypothermia in postmortem
imaging?

CQ17

What findings are useful in estimating starvation while alive on
postmortem CT scans?

CQ18

Is it possible to diagnose malignant neoplasms on postmortem CT scans?

CQ19

Can postmortem imaging diagnose the direct cause of death due tomalignant neoplasms?

CQ20

What radiological findings are useful in the diagnosis of pneumonia with

postmortem CT scans?
CQ21

Is postmortem imaging useful when determining death from asphyxia?

CQ22

Is it possible to use postmortem imaging to detect drugs in the stomach?

CQ23

Is postmortem imaging useful to detect and measure fluid in body cavities?

CQ24

Is it possible to use postmortem imaging to detect and quantify gas incorpses?

CQ25

Is postmortem imaging useful in determining rib fractures arising fromcardiopulmonary resuscitation?

CQ26

Is postmortem imaging useful in diagnosing visceral injuries due tocardiopulmonary resuscitation?

CQ27

Is postmortem imaging useful in diagnosing causes of death duringexternal examinations of cadavers?

CQ28

Is it useful to use postmortem radiography before autopsies?

CQ1 What are postmortem changes that can be visualized in postmortem images?
Grade of recommendation: C1
In contrast to antemortem images, many of the features of postmortem images are
non-specific, including hypostasis, and hyperattenuation of structures such as theaortic walls and sinuses. These features are similar to those in antemortem images,
however they may be difficult to identify on postmortem images, and therefore caremust be shown when reading postmortem images (see the chart for a summary of
the body sites).
As the postmortem image findings change and become more pronounced with time,
it is also important to take into account the time elapsed since death.
Explanation
As postmortem imaging is affected by postmortem changes, it differs from imaging
performed in the clinical setting. Cardiopulmonary resuscitation also affects
postmortem imaging (CQ23–25). Thus, it is necessary to be careful not to
mis-interpret postmortem images. It is necessary to establish “normal” postmortem
image findings and features that could indicate the cause of death, and to organize
this knowledge.
Postmortem changes
Biological death is confirmed following the arrest of circulation, breathing, andbrainstem functioning. In dead bodies (cadavers), postmortem changes due to thearrest of circulation vary according to the time elapsed since death. These occur inthe same manner as those seen on the external surface of the body; are influenced
mainly by gravity and bacterial activity; and are affected by position, temperature,and the place where the dead body is stored. Changes occurring within a few days
after death are termed early postmortem changes, whereas those occurring later
are termed delayed postmortem changes. Early postmortem changes include fallingbody temperature, corneal opacity, livor mortis, and rigor mortis. Among these, livor
mortis can be detected on images as hypostasis. Following the arrest of circulation,
the blood in vessels and organs pools in the back and the lower parts of the body due
to the effect of gravity. Hypostasis is depicted as areas of higher density than thatseen in surrounding tissue, and is visualized most commonly in the area of thelungs and the intracranial sinuses. In contrast, delayed postmortem changes

include autolysis, putrefaction, skeletonization, and mummification. During
putrefaction, gas forms inside blood vessels, organs, and soft tissue by the action ofbacteria. The ability of computed tomography to detect gas means that gas may
sometimes be depicted as early as a few hours after death.
Postmortem image findings
Postmortem image findings comprise the antemortem clinical conditions causing
death, those due to cardiopulmonary resuscitation, and postmortem changes. Thechanges due to cardiopulmonary resuscitation include those caused by chest
compression (closed-chest cardiac massage), artificial respiration, and othertreatments administered at cardiopulmonary arrest (CQ23-25). Typical postmortem
changes that do not normally appear in antemortem images are listed in the table;
these include hypostasis (CQ3) and gas from putrefaction. These changes are
non-specific in postmortem images, and do not imply abnormal findings (figure) (1)(2).
Even if the postmortem findings are similar to those in antemortem images, theunderlying pathological mechanism and interpretation of the findings may bedifferent (1).
It should be noted that here we discuss characteristic normal postmortem findings,
rather than provide an exhaustive list.
The longer time has passed, the stronger the postmortem changes appear
A study performed by computed tomography immediately after death and again atmore than one day after death found that the later images were influenced andmodifiedbypostmortem

changes,

and

that

these

changes

could

cause

misinterpretation. Images obtained immediately after death are only little
influenced by postmortem changes, and are therefore suitable for determining thecause of death or the course of illnesses, while those obtained more than one day
after death reflect the findings of a pathological autopsy. It is necessary to have an
understanding of the differences and characteristics to enable these two phases ofpostmortem images to be utilized. Repeated scans at different time periods andcomparisons with an autopsy will enable improvement in our knowledge of
postmortem changes and thus increase the accuracy of image interpretations.
As the postmortem changes themselves change over time, the time elapsed sincedeath is an important factor that should be carefully considered when interpreting
postmortem images.

Key words
Postmortem, CT imaging, autopsy, Cause of death; Search within 10 years
References
1. Christe A et al: Clinical radiology and postmortem imaging (Virtopsy) are not thesame: Specific and unspecific postmortem signs. Leg Med (Tokyo) 12: 215-222, 2010
(Level 5)
2. Shiotani S et al: Autopsy imaging: postmortem findings are classified into causeof death, changes by cardiopulmonary resuscitation, and postmortem changes.
Gazou Shindan 30: 106-120, 2010 (Level 5)
3. Shiotani S et al: Postmortem pulmonary edema: a comparison between
immediate and delayed postmortem computed tomography. Leg Med (Tokyo) 13:
151-155, 2011 (Level 5)

FigurePostmortem chest CT scan showing hyperattenuation of the aortic wall andhypostasis.

(A) The wall of the enlarged ascending aorta shows high attenuation (▲). There is aclear separation between areas of higher and lower attenuation, which form a level
perpendicular to gravity (→). The appearance of hypostasis is similar to that oferythrocyte sedimentation.
(B) Ground glass attenuation is evident throughout the lung area, and is more
prominent in the lower part of the body than on the ventral side (→). The
appearance is characteristic of hypostasis.

TableCharacteristic postmortem CT findings of a traumatic death (cited from references
1, 2; partly modified)
Chest

Abdomenaortic dissection

rupture of aortic aneurysms

rupture of aortic aneurysms

intraperitoneal free gas

ischemic heart disease(gastrointestinal perforation)(pulmonary edema due to pumping
dysfunction)
pulmonary thromboembolism(enlargement of the hilar pulmonary artery)
cardiovascular gas

intrahepatovascular (portal and hepatic veins)gas

rib fractures

dilation of the gastrointestinal tracthypostasis (cardiovascular system, lungs)

intrahepatic gas

enlargement of the right side of the heart
hyperattenuation of the aortic wall
decomposition (intravascular gas)decomposition (intravascular gas)CQ2 Are all high densities in the cranium hemorrhages?
Grade of recommendation: C2
Intracranial high densities may appear in some non-hemorrhagic states or as
postmortem changes on postmortem head CT scans. It is known that hypostasis in
the dorsal venous sinuses show as high densities. Cisterns may show high density
as in case of sequels to cerebral edemas in acute cerebral infarctions and also inother cases. Such non-hemorrhagic states must be distinguished from intracranial
hemorrhages.
Explanation
Head CT scans are useful to diagnose intracranial hemorrhages, which present highdensities, clinically. High densities due to postmortem changes or non-hemorrhagic
states, which resemble intracranial hemorrhages, must be distinguished fromintracranial hemorrhages on postmortem CT scans.
Intracranial high densities as a postmortem change
It is known that hypostasis in the dorsal venous sinuses show as high densities. In
some reports, the autopsies have established that cranial high densities on
postmortem CT scans were normal venous sinus or congestive cerebellar tentorium.
In particular, hypostasis is clearly observed in neonates and infants. Because of thehigh water content of the brain, brain parenchyma shows low attenuation shapes onhead CT scans. Hypostasis is commonly observed along the falx cerebri, orbilaterally symmetrical dorsal sinuses.
Intracranial high densities due to brain edema
Intra-cisternhighdensities,

which

are

known

as

Pseudo-subarachnoid

hemorrhages, may be seen (occur) in patients with cerebral edema due to acutecerebral infarction, and for other reasons. Such findings may be seen on
post-mortem CT scans in decedents with acute cerebral infarction with cerebral
edema.

Figurehigh density at the posterior fossa

High density present at the superior sagittal and transversus sinuses, resembling
subdural hematomas.
This CT image was reported for a skull bone fracture and subdural hematoma. At
the autopsy, there is no skull bone fracture and no subdural hematoma. The arrowis the diploic vein (canal).

CQ3 Can hypostasis and clotting in the heart or blood vessels be distinguished fromthrombosis by postmortem CT scans?
Grade of recommendation: C2
Hypostasis and clotting in the heart or great vessels which appear after the
cessation of circulation are often observed on postmortem CT/MRI scans. It isthought that there is a possibility of misdiagnosis because these postmortem
changes are similar to thrombosis in living humans. There are a number of reportsof the features of hypostasis and clotting like the postmortem changes or thrombosis
as a pathologic condition, however, the diagnosis of thrombosis by postmortem
CT/MRI images needs to be made with great care.
Explanation
hypostasis, sedimentation
Hypostasis occurs after circulation has ceased. The plasma and cellular componentsof the blood are subject to gravity and initially sink and become sediment in theheart and vascular system. Hyperdense areas on the dependent side and hypodenseareas on the independent side with mirror surfaces exhibit hypostasis on PMCT (1).
On postmortem MRI scans, hypostasis is observed as low signal intensity areas on
the dependent side (due to the iron content of the hemoglobin in sedimented red
blood cells) and high signal intensity areas on the independent side of T2-weighted
images. However, this state does not show steady signal because the postmortem
elapsed time can affect MR signal intensity (2). It is reported that the clarity ofhypostasis on postmortem CT scans differs among cases and is related to theantemortem serum fibrinogen score (3). The status such as the position ortemperature of preserved cadavers may affect findings of hypostasis.
intravascular clotting
Blood clotting as a postmortem change is considered to occur in the state of long
agonal stages or chronic disease deaths. Clotting varies in density and form, and"mold-like" hyperdense columnar structures similar to pulmonary arterial
thrombosis are often observed (4-7). It is considered that the formation of clotting is a
gradual postmortem change and hypostasis is sometimes noted in the clot. The
parallel occurrence of hypostasis becomes uncertain as broad clotting includes many
blood cells. Clotting is also affected by the situation of the death or temperature ofthe preserved cadaver and possibly occurs in situations such as deaths by freezingor burning (8,9). In addition, hypostasis and clotting is easier identified on MRI thanon CT scans (2).
Distinguishing of hypostasis and thrombosis
pulmonary artery thrombosis
Takahashi et al. reported a case of pulmonary arterial thrombosis which wassuspected by a postmortem CT scan and proved by the autopsy. Dilatation of thehilum pulmonary artery and narrowing of peripheral pulmonary artery thrombosis
were observed on the postmortem CT scan (10). Some clinical studies report that
acute pulmonary artery thrombosis may to some degree be diagnosed byunenhanced CT scans (11,12). It is considered that thrombi are easily identified in the
middle of the side of the pulmonary artery and that the density of the thrombi
varies. Although secondary findings of dilatation of the pulmonary artery whichreflects pulmonary hypertension due to pulmonary arterial thromboembolism or of
the right heart are occasionally observed on postmortem CT scans, it is necessary tocarefully interpret these findings because dilatation of the right heart occurs as anormal postmortem change due to the cessation of circulation (13). When pre-mortem
pulmonary thrombosis is suspected by a postmortem CT scan, it is difficult todistinguish between acute and chronic pulmonary thrombosis. The form of chronic
pulmonary thrombosis varies from band-like to meshed and others (14).
On postmortem MRI images, the finding of blood clots before death sometimes
reflects the deposit of hemosiderin. Therefore, postmortem MRI scans can possibly
distinguish acute from chronic thrombosis (6). It is reported that hypostasis in bloodclots before death are not observed and that such clots show a homogeneous form
continuous with the vascular wall (15). However, there are also reports that bloodclots as a postmortem change in the cardiac cavity are not adjacent to theventricular wall (6,7). The localization and form in the cardiac or vascular lumen, its
angle, and irregularities of the border of the density/signal may be helpful in adifferential diagnosis of hypostasis, clots, and/or thrombosis on postmortem CT/MRI
images.
Hypostasis reflected in postmortem changes or blood clots are often observed on
postmortem CT/MRI images, and it may be difficult to establish diagnoses of thesefindings and pulmonary artery thrombosis on unenhanced CT/MRI images.
However, it may be possible to suspect pulmonary thromboembolism by evaluating
the form or density of the pulmonary artery (referring to multi-planar reconstructedimages). Additionally, Clinical information such as sudden chest pain, dyspnea,
cardiopulmonary arrest, and similar will be useful.
Recent studies by Jackowski et al. show that thromboembolisms can be
distinguished from blood clots on postmortem unenhanced 3T-MRI images.
coronary artery thrombosis
Jackowski et al. reported that thromboembolism of the left anterior descending
artery could be diagnosed on postmortem MRI images. Thrombus should besuspected because homogeneous light, high signal intensities without hypostasis in
the narrowed arterial lumen has been established in T2-weighted images (17). Low
signal intensity findings between the anterior and base walls and the ventricular
septum on T2-weighted images with suspected hyper-acute myocardial ischemia
supported the diagnosis of coronary artery thrombosis.
Michaud et al. reported that hypostasis in the ascending aorta extended to the left
coronary artery and blood clots were formed in the coronary artery (18). The
important point here is that clots in the coronary artery were not diagnosed as
thrombosis. Hyperdensity in the coronary artery with continuity to the obvious
hypostasis in the ascending aorta should not immediately be diagnosed as
thrombosis and this leads to the possibility of disregarding the diagnosis ofthrombosis here. Conversely, it is considered that excluding thrombosis is difficult
when hypostasis and blood clots are not clearly identified.
Remarks
Thrombosis of the pulmonary artery and coronary artery is mentioned in thissection. Further studies of other kinds of thrombosis such as pulmonary vein orsinus thrombosis can be expected to be reported.
Research methodology and supplementary materials
The following terms were searched for on PubMed: postmortem, forensic, CT,
computed tomography, MRI, magnetic resonance imaging, thrombosis, thrombus,
embolus, embolism, hypostasis, sedimentation, clot, clotting, coronary, pulmonary,thromboembolism. Books entitled “autopsy imaging guide for interpretation” and“autopsy imaging cases series” were also used in this survey.

References

1. Shiotani S, et al: Postmortem intravascular high-density fluid level (hypostasis):
CT findings. J Comput Assist Tomogr 26:892-3, 2002 (level Ⅴ)
2. Jackowski C, et al: Postmortem imaging of blood and its characteristics using
MSCT and MRI. Int J Legal Med 120:233-40, 2006 (level Ⅴ)
3. Ishida M, et al: Hypostasis in the heart and great vessels of non-traumatic
in-hospital death cases on postmortem computed tomography: relationship toantemortem blood tests. Leg Med (Tokyo) 13:280-5, 2011 (level Ⅳ)
4. O'Donnell C, et al: Post-mortem radiology--a new sub-speciality? Clin Radiol
63:1189-94, 2008 (level Ⅳ)
5. Jackowski C, et al: Postmortem imaging of blood and its characteristics using
MSCT and MRI. Int J Legal Med 120:233-40, 2006 (level Ⅴ)
6. Patriquin L, et al: Postmortem whole-body magnetic resonance imaging as an
adjunct to autopsy: preliminary clinical experience. J. Magn. Reson. Imaging
13:277-87, 2001 (level Ⅴ)
7. Uekita I, et al: Medico-legal investigation of chicken fat clot in forensic cases:
immunohistochemical and retrospective studies. Leg Med (Tokyo) 10:138-42, 2008(level Ⅴ)
8. Kawasumi Y, et al: Hypothermic death: possibility of diagnosis by post-mortem
computed tomography. Eur J Radiol 82:361-5, 2013 (level Ⅳ)
9. Takahashi N, Shitani S, ed. Autopsy imaging case series, Vector Core, Tokyo,
pp102, 2012 (level Ⅴ)
10. Tatco VR, et al: The validity of hyperdense lumen sign in non-contrast chest CT
scans in the detection of pulmonary thromboembolism. Int J Cardiovasc Imaging
27:433-40, 2011 (level Ⅳ)
11. Cobelli R, et al: Clinical usefulness of computed tomography study without
contrast injection in the evaluation of acute pulmonary embolism. J Comput Assist
Tomogr 29:6-12, 2005(level Ⅳ)
12. Shiotani S, et al: Dilatation of the heart on postmortem computed tomography(PMCT): comparison with live CT. Radiat Med 21:29-35, 2003 (level Ⅴ)
13. Rajaram S, et al: Diagnostic accuracy of contrast-enhanced MR angiography andunenhanced proton MR imaging compared with CT pulmonary angiography inchronic thromboembolic pulmonary hypertension. Eur Radiol 22:310-7, 2012 (levelⅣ)
14. Barkhausen J, et al: Detection and characterization of intracardiac thrombi on
MR imaging. Am J Roentgenol 179:1539-44, 2002 (level Ⅴ)
15. Jackowski C, et al: Pulmonary thrombembolism as cause of death onunenhanced postmortem 3T MRI. Eur Radiol 23:1266-70, 2013 (level Ⅴ)
16. Jackowski C, et al: Coronary thrombus and peracute myocardial infarction
visualized by unenhanced postmortem MRI prior to autopsy. Forensic Sci Int
214:e16-9, 2012 (level Ⅴ)
17. Michaud K, et al: Evaluation of postmortem MDCT and MDCT-angiography forthe investigation of sudden cardiac death related to atherosclerotic coronary arterydisease. Int J Cardiovasc Imaging 28:1807-22, 2012 (level Ⅴ)

FigureAn autopsy case of a pulmonary thromboembolism

Although the pulmonary artery seems to be dilated compared with the aorta, afinding that suggests blood clot or thrombus in the main trunk of pulmonary arteryis not observed. It is observed that significant bilateral consolidation is mainly inthe hilum (A). A uterus tumor is observed in the pelvis and a finding of iliac arteryand vein compression by this tumor is observed (B). Comparing with the right
popliteal vein, the left popliteal vein is tense and hyperdense (C). The autopsy
showed thromboembolism in the bilateral intrapulmonary arteries (D). Thrombosis
in the vein of the left popliteal fossa and lower leg muscle were also identified (E)the arrow in the cranial side).

CQ4 What are useful findings to suggest deaths due to external causes inpostmortem images?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
The findings that are useful to suggest deaths due to external causes include
trauma such as bone fractures or subdural hematomas, drowning-related findings,
findings associated with neck compression such as hyoid fractures, foreign objects
in the airways, overdose-related findings in the stomach, hypothermia-related
findings, gas embolisms, and abuse-related findings.
Explanation
The definition of deaths due to external causes
Deaths due to external causes are all kinds of causes of death except “deaths by
diseases and natural deaths” and “undetermined deaths” as detailed in deathcertificates in Japan 1). In death certificates in Japan, deaths due to external causes
are classified into unexpected accidental deaths (traffic accidents/ falling/ drowning/
injuries due to smoke, fire, and flames/ asphyxia/ intoxication/ and others) and otherdeaths due to external causes (suicides/ homicides/ causes undetermined). As
emphasized in the guidelines for unnatural deaths produced by the JapaneseSociety of Legal Medicine2), deaths due to sequela or after effects of injuries fromexternal causes or deaths associated with medical treatment must be treated as
deaths due to external causes. However, these kinds of deaths are not included inthis section because the present guidelines are for dealing with deaths fromundetermined causes occurring outside hospitals.
BackgroundIn this section, only postmortem computed tomography (PMCT) studies without
using contrast media are included because this is the most used modality forpostmortem images in Japan.
Although there are some studies referring to the possibility of determining causes ofdeath by PMCT scans based on comparisons with autopsy results, most of these
discuss only “causes of death” 3-8). Few discuss the “manner (way) of death”
including deaths caused by external causes. Generally, as in some of these reports,

the “manner of death” can be determined only in comprehensive ways using all of
the information associated with the cadavers involved, including investigation of
the situation by law enforcement officers, or toxicological findings, and are neverdetermined simply by findings based on images.
In Japan, even if a cadaver is discovered outside hospitals, once law enforcement
officers establishes that it is not related to a crime, autopsies are not to be
performed. However, in some of such cases, PMCT scans are still made, and the
PMCT scans may show findings suggesting death due to external causes, which law
enforcement officers probably would not have expected before the scan wasavailable 9,10). Sometimes law enforcement officers initially suspect death by disease,
but PMCT scans find this to be wrong 11). In this situation, the PMCT scan reader
who makes this discovery must persuade the police to change their determination.
It may be said that for PMCT scan readers of cadavers discovered away from
hospitals, a minimal requirement would be to check for the presence or absence offindings suggesting deaths due to external causes in deciding the causes of death.
In the following several sections, simple explanations and caution related to image
findings of different kinds of deaths due to external causes are detailed. As these
topics are also discussed in other sections of this guideline, it is recommended tocheck the respective sections of this book for the different topics.
Trauma deaths
For 5 of 20 cadavers Hayakawa et al. reported that PMCT scans showed findings
suggesting deaths due to external causes which were not initially identified byexternal examinations. In 3 of the 5 cases, the findings were related to trauma (2 tosubdural hematomas and 1 to liver contusion) 9). For 10 of 80 cadavers Iwase et al.
reported that PMCT scans showed findings suggesting deaths due to externalcauses. In 7 of the 10 cases, the findings were related to trauma (4 to subdural
hematomas, 1 to stab wounds to the heart, 1 to traumatic tension pneumothorax,
and 1 to abdominal organ injury) 10). For 3 of 494 cadavers that were initiallythought to be from deaths by diseases, Takahashi et al. reported that PMCT scans
showed trauma including 2 of multiple trauma and 1 of cervical neck injury. As
these reports from Japan show, the most common findings suggesting deaths due toexternal causes which were not initially detected by external examination or police
investigations is trauma. This suggests the need for PMCT scan interpreters to pay
attention to possible hidden trauma symptoms in reading the images.
In multiple reports comparing PMCT scan observations with autopsy findings,

agreement with trauma-related findings was confirmed

3,

4,

6-8,

12-17).

In ameta-analysis performed by Scholing et al., agreement between the PMCT and
autopsy findings of traumatic deaths reached 46-100% of the causes of death, and53-100% in the specific trauma determined17). Further large-scale research isneeded to narrow these large differences. However, they show that at least about
half of trauma cases can be detected by PMCT scans. The trauma findings, which
are referred to as detectable lesions by the PMCT scan readings similar to autopsies
in many reports, are bone fractures and fatal hemorrhages inside the cadavers suchas intracranial hematomas or retroperitoneal hemorrhages. These findings need
PMCT scans for the detection, but as these reports suggests, attention is required
for trauma detection because even fatal trauma can be missed by PMCT scans insome cases. This is emphasized in detail in CQ5.
Drowning
As stated in CQ15, the findings suggesting drowning include fluid collection in theparanasal sinuses, fluid collected in the trachea and bronchi, and ground-glass
opacities in the lungs and all have been reported 18). If the PMCT scan readers arefamiliar with these findings, it becomes possible to assume drowning as a cause ofdeath by looking at PMCT scans, at least to some extent. However, these PMCT
scan findings are non-specific, and for an accurate diagnosis of drowning the diatom
detection inside the bodies and excluding other causes of death are needed,something which PMCT scans cannot achieve. Besides, to determine why the
cadaver came to be in the water (accident or pushed by someone) it is recommended
to consult autopsies and law enforcement authorities.
Fire related deaths
The findings to be evaluated for a diagnosis of fire-related death include soot in the
airways, blood concentration of carbon monoxide, and extent of burns, none of which
can be evaluated by PMCT scans. However, PMCT scans are useful to determine
whether a cadaver was shot or not prior to the autopsy 19,20) since gunshot wounds
exposure to soot is difficult to evaluate from external examinations of charredcadavers. Levy reports that PMCT scans are also useful to evaluate whether skull
fractures are traumatic or occurred postmortem, formed by heat 19). Overall PMCT
scans are useful to determine unexpected causes of death due to external causes infire-related cases.

Asphyxia
There are PMCT scan findings suggesting asphyxia due to neck compression(hanging, strangulation, manual strangulation), and fractures of cervical bones andcartilage such as hyoid fractures 8,21). Further, it is reported that foreign objects inthe airways can be identified by PMCT scans, which is useful to determine asphyxia
due to aspiration of foreign objects 22, 23) (CQ21).
Much caution in interpreting images on this topic are necessary, including: that
there are no other useful findings to detect some kinds of asphyxia especially
suffocation due to obstruction of the orifice of the mouth and nose, that no fractures
occur in many cases of neck compression, and that PMCT scans are not useful toshow vital reactions of asphyxia including petechiae, showing that great care must
be shown before deciding on a cause of death here.
Intoxication
As a diagnosis of death due to intoxication needs toxicological examinations fromcadaver samples like femoral blood, there are no definite findings to determine
intoxication deaths by PMCT scans. However, as in CQ22, there are cases ofoverdoses, high-density gastric and duodenal contents derived from ingested tablet
components that can be detected by PMCT scans, and PMCT readers need to pay
attention to, as these could be a key to establish death by intoxication 24).
Others
It may be necessary to look for findings suggesting hypothermic states at death(low-density lungs, clot formation inside the heart and aorta, increased urine
volume in the bladder) 25, 26). Care must be taken for such a diagnosis because
hypothermic death needs to consider reasons why the victim could not escape fromthe cold environment (CQ16).
Gas embolism is a very rare cause of death due to external causes. There are manycase reports of PMCT scans which detected intravascular gas in suspected cases
27-29). Intravascular gas can also be generated postmortem and it is important toknow the “normal” postmortem gas distribution for a diagnosis of gas embolisms.
If PMCT scans show findings suggesting chronic physical abuse such as old rib
fractures in the cases of child deaths, deaths due to external causes must be
considered, even if the findings are not sufficiently serious to be fatal 7) (CQ31).
*Deaths due to external causes are classified into “manners of death”, and thesecannot be determined without investigations performed by law enforcement officers
and autopsy results including toxicological examinations. If PMCT scan readers
identify findings suggesting deaths due to external causes, these readers must atleast be able to persuade law enforcement officers to reconsider conclusions with
newly established findings.
Search formula・secondary references
The authors performed the search on Pubmed for the past 10 years using combined
keywords as follows; “postmortem CT” or “postmortem imaging” or “forensic
radiology” or “virtual autopsy” or “virtopsy”, autopsy, cause of death, and trauma.
Besides, the manual for death certificates (2014) (from the homepage of the Health,Labour and Welfare Ministry http://www.mhlw.go.jp/toukei/manual/) 1) and themanual for unnatural deaths produced by the Japanese Society of Legal Medicine
(from

the

homepageoftheJapanese

Societyof

Legal

Medicine

http://www.jslm.jp/public/guidelines .html) 2) have been consulted.
Reference
1. Manual to fill in a death certificate (2013)（Homepage of Health, Labour and Welfare
Ministry http://www.mhlw.go.jp/toukei/manual/）

2. Guidelines for notification of unnatural death, Japanese Society of Legal Medicine（http://www.jslm.jp/public/guidelines.html）
3.

Thali MJ, et al: Virtopsy, a new imaging horizon in forensic pathology: virtual

autopsy by postmortem multislice computed tomography (MSCT) and magnetic
resonance imaging (MRI)--a feasibility study. J Forensic Sci 48:386–03, 2003 （levelⅣ）
4. Leth PM: Computerized Tomography Used as a Routine Procedure at
Postmortem Investigations. Am J Forensic Med Pathol 30:219–22, 2009 （levelⅣ）
5. Roberts IS, et al: Post-mortem imaging as an alternative to autopsy in the
diagnosis of adult deaths: a validation study. Lancet 379:136–42, 2012 （levelⅣ）
6. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14:239–45, 2012 （levelⅣ）
7. Proisy M, et al: Whole-body post-mortem computed tomography compared with
autopsy in the investigation of unexpected death in infants and children. Eur Radiol
23:1711-9, 2012 （levelⅣ）

8. Blanc-Louvry I, et al: Post-mortem computed tomography compared to forensic
autopsy findings: a French experience. Eur Radiol 23:1829-35, 2013 （levelⅣ）
9. Hayakawa M, et al: Does imaging technology overcome problems of conventional
postmortem examination? Int J Legal Med 120:24-6, 2005 （levelⅤ）
10. Iwase H, et al: Evaluation of computed tomography as a screening test for deathinquest. J Forensic Sci 55: 1509–15, 2010 （levelⅤ）
11. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22:152-60, 2012 （levelⅣ）
12. Yamazaki K, et al: Comparison between computed tomography (CT) and autopsy
findings in cases of abdominal injury and disease. Forensic Sci Int 162:163–6, 2006
（levelⅤ）
13. Levy G, et al: Postmortem computed tomography in victims of military air
mishaps: radiological-pathological correlation of CT findings. Isr Med Assoc J
9:699-702, 2007 （levelⅣ）
14. Hoey BA, et al: Postmortem computed tomography, “CATopsy,” predicts cause ofdeath in trauma patients. J Trauma 63:979-89, 2007 （levelⅣ）
15. Sochor MR, et al: Postmortem computed tomography as an adjunct to autopsy
for analyzing fatal motor vehicle crash injuries: Results of a pilot study. J Trauma
65:659-65, 2008 （levelⅣ）
16. Christe A, et al: Abdominal trauma—sensitivity and specificity of postmortem
noncontrast imaging findings compared with autopsy findings. J Trauma 66:1302-7,
2009 （levelⅣ）
17. Scholing M, et al: The value of postmortem computed tomography as analternative for autopsy in trauma victims: a systematic review. Eur Radiol
19:2333-41, 2009 （levelⅠ）
18. Levy AD, et al: Virtual autopsy: two- and three-dimensional multidetector CT
findings in drowning with autopsy comparison. Radiology 243:862-8, 2007 （levelⅤ）
19. Levy AD, et al: Multidetector computed tomography findings in deaths withsevere burns. Am J Forensic Med Pathol 30:137-41, 2009 （levelⅤ）
20 Sano R, et al: Use of postmortem computed tomography to reveal an intraoral
gunshot injuries in a charred body. Leg Med (Tokyo). 13:286-8, 2011 （levelⅤ）
21. Kempter M, et al ： Post-mortem imaging of laryngohyoid fractures in
strangulation incidents: First results. Leg Med (Tokyo) 11:267-71, 2009 （levelⅤ）.
22. Oesterhelweg L, et al: Virtopsy: postmortem imaging of laryngeal foreign bodies.
Arch Pathol Lab Med 133:806-10, 2009 （levelⅤ）23. Iino M, et al: Postmortem computed tomography findings of upper airway
obstruction by food. J Forensic Sci 55:1251-8, 2010 （levelⅤ）
24. Burke M, et al: The use of postmortem computed tomography in the diagnosis ofintentional medication overdose. Forensic Sci Med Pathol 8:218-36, 2011 （levelⅣ）
25. Kawasumi Y, et al: Hypothermic death: possibility of diagnosis by post-mortem
computed tomography. Eur J Radiol 82:361-5, 2013 （levelⅣ）
26. Hyodoh H, et al: Postmortem computed tomography lung findings in fatal of
hypothermia. Forensic Sci Int 231:190-4, 2013 （levelⅣ）
27. Plattner T, et al ： Virtopsy–Postmortem Multislice Computed Tomography(MSCT) and Magnetic Resonance Imaging (MRI) in a Fatal Scuba Diving Incident.
J Forensic Sci 48:1347-55, 2003 （levelⅤ）
28. Jackowski C, et al: Visualization and quantification of air embolism structure byprocessing postmortem MSCT data. J Forensic Sci 49:1339–42, 2004 （levelⅤ）
29. Makino Y, et al: Massive gas embolism revealed by two consecutive postmortem
computed-tomography examinations. Forensic Sci Int 231:e4-10, 2013 （levelⅤ）

CQ5 Is it possible to exclude all deaths due to external causes by postmortem
imaging?
Grade of recommendation: D
There are some deaths due to external causes such as intoxication or some cervical
cord injuries that will not yield positive findings by PMCT scans. Also, some positive
findings likely to be diagnosed as deaths by diseases such as subarachnoid
hemorrhages, cerebral infarction, or rupture of aortic aneurysms have the potential
to be diagnosed as deaths due to external causes depending on the situation. Thus,
it is not recommended to use postmortem imaging to rule out deaths due to externalcauses and careful evaluation is needed.
Explanation
Background
It may be that non-contrast postmortem computed tomography (PMCT) studies
suggest deaths due to external causes even if police officers initially have alreadydetermined that the cadaver has no relation to a crime1,2). Suspicion of death due toexternal causes can be provoked for the first time by PMCT scans even if physicians
initially consider that a case was death by disease3).
Comparison studies between PMCT scans and autopsies (CQ4)
Deaths due to external causes are classified into different “manners of death”,
which should be determined from autopsy results as well as from comprehensive
information including investigations to determine details of situations andtoxicological examinations. There are no studies that have concluded that only
PMCT scans can finally decide the causes of deaths due to external causes
comparing determinations by PMCT scans and autopsies.
Continuous case series studies with relatively high volumes of cases, all haveconcluded that PMCT scans cannot diagnose intoxication or fire-related deaths 4-8).
For drowning, there are some reports saying that this can be diagnosed by PMCT
scan findings, but most have concluded that the findings are non-specific and that adefinite diagnosis by PMCT scans alone is difficult. This is similarly said forasphyxia cases.
Even traumatic deaths, which are thought to be the simplest to detect by PMCT
scans among deaths due to external causes, there is a wide-range of successful

detection with (50-100%) depending on the report9). Reasons for the low detection
rate of trauma by PMCT scans are that it is difficult to detect some causes of fatal
trauma including vascular injuries, cervical cord injuries, lung contusion, and liver
contusion. It is also important to be aware of the difficulty to know whether signs of
trauma are formed antemortem or postmortem, here the detection rate of “vital”
trauma cases would decrease further4,8,10).
There are some deaths due to external causes that appear like deaths by diseases on
PMCT images. For example, it is also stated in the topic of subarachnoid
hemorrhages in CQ12, that there are cases of traumatic rupture of the vertebral orbasilar arteries with large amounts of subarachnoid hematomas on the basal
cisterns misleading readers to diagnose this as subarachnoid hemorrhages due torupture of cerebral artery aneurysms6). This could similarly occur in traumatic
cerebral infarctions, traumatic cardiac tamponade, or traumatic ruptures of aortic
aneurysms.
In summary, when considering the many problems detailed above, it seems difficult
to exclude all deaths due to external causes only by PMCT scans. To determine to
exclude deaths due to external causes, careful evaluations are needed from PMCT
scan findings as well as from comprehensive information such as the investigation
information from law enforcement officers or results of toxicological examinations.
Search formula・secondary references
The authors performed the search on Pubmed for the past 10 years using combined
keywords as follows; “postmortem CT” or “postmortem imaging” or “forensic
radiology” or “virtual autopsy” or “virtopsy”, autopsy, cause of death, and trauma.
Reference
1. Hayakawa M, et al: Does imaging technology overcome problems of conventional
postmortem examination? Int J Legal Med 120:24-6, 2005 （levelⅤ）
2. Iwase H, et al: Evaluation of computed tomography as a screening test for deathinquest. J Forensic Sci 55: 1509–15, 2010 （levelⅤ）
3. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22:152-60, 2012 （levelⅣ）
4. Thali MJ, et al: Virtopsy, a new imaging horizon in forensic pathology: virtual
autopsy by postmortem multislice computed tomography (MSCT) and magnetic

resonance imaging (MRI)--a feasibility study. J Forensic Sci 48:386–403, 2003
（levelⅣ）
5. Leth PM: Computerized Tomography Used as a Routine Procedure at
Postmortem Investigations. Am J Forensic Med Pathol 30:219–22, 2009 （levelⅣ）
6. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14:239–45, 2012 （levelⅣ）
7. Proisy M, et al: Whole-body post-mortem computed tomography compared with
autopsy in the investigation of unexpected death in infants and children. Eur Radiol
23:1711-9, 2012 （levelⅣ）
8. Blanc-Louvry I, et al: Post-mortem computed tomography compared to forensic
autopsy findings: a French experience. Eur Radiol 23:1829-35, 2013 （levelⅣ）
9. Scholing M, et al: The value of postmortem computed tomography as analternative for autopsy in trauma victims: a systematic review. Eur Radiol
19:2333-41, 2009 （levelⅠ）
10. Iwase H, et al: Can cervical spine injury be correctly diagnosed by postmortem
computed tomography? Leg Med (Tokyo) 11:168–74, 2009 （levelⅤ）

CQ 6 In postmortem radiography, what findings are useful to determine death fromnatural causes?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
Extravascular retention of bleeding such as from cerebral hemorrhages orhemopericardium (hematomas in the cardiac sac) by aortic dissection, is useful inthe diagnosis of diseases as internal causes of death. Depending on the degree, it
may be considered to be deaths from internal causes.
Refer to other chapters CQ6-9, CQ15-16 such as for Subarachnoid hemorrhages (→CQ7), Cerebral hemorrhages (→ CQ8), Aortic dissections (→ CQ9).
It is thought that disease findings for clinical diagnosis are also useful.
We consider such findings for the disease. We have to examine carefully todetermine a disease as the cause of death, while external causes of death should be
excluded
Explanation
Definition of an internal cause of deathInternal cause of death is used as the opposite of "external cause of death", theso-called natural death.
Those refer to death due to natural diseases other than trauma or causes by foreign
substances/

environment,

however,

includingdeathsfrominfectionofmicroorganism such as viruses or bacteria.
The postmortem CT scan findings useful for diagnosis of an internal cause of death
In determining the cause of death, it is very important to distinguish internal fromexternal causes in the view of forensic medicine. As image findings, we deal withfindings of clinical diseases. There are some cases where it is difficult to make adetermination even from autopsy findings.
1. Findings to indicate diseases that are important
It is useful to establish findings of hemopericardium with aortic dissection and apost MI cardiac rupture among disorders of the heart and large vessel system. It
can be a ground for a determination to specify the site of a rupture by postmortem
angiography. (10)

2. It is more difficult to diagnose natural deaths than deaths from external causes.
(39)
Brain subarachnoid hemorrhages
Subarachnoid hemorrhages may be strongly suspected as the cause of death,especially when there is a dense subarachnoid hemorrhage at the base of the brain,
subarachnoid hemorrhage with intraventricular hemorrhage, and subarachnoid
hemorrhage with pulmonary edema. (CQ7)
Cerebral hemorrhage
Cerebral hemorrhages can be strongly suspected as the cause of death when there isbrain stem hemorrhage, bleeding of more than 30 cm3, bleeding to overcome orpressure the ventricle, cerebral hemorrhage with a midline shift of 5 mm or more.
(CQ8)
Hemopericardium (hemorrhage in the cardiac sac)
When we observe a high density area occupying pericardial space, the presence of ahemorrhage in the pericardium can be recognized. Large hemorrhage quantities
indicate suspects for the cause of death.
It is difficult to show the cause of bleeding and to diagnose the primary cause ofdeath.
Post MI cardiac rupture, aortic dissection and pericarditis should be diagnosed
differentially. (CQ?)
Aortic aneurysm ruptures / Aortic dissection
We can determine this disease when there is a large quantity of bleeding.
When there are pools of blood, applanation of large vessels, rhexis of vascular tissue
with false cavities and circulation oligemia, this can be strongly suspected. (CQ?)
Malignant tumor
We can point out tumors such as malignant tumors of lungs, bronchi, a pleura, apharynx, bowel, liver, brain, and adrenal. However, it is difficult to diagnose an
origin and tissue form of a tumor or whether it is primary.
We should diagnose totally findings about sequence syndrome, but it is difficult todetermine the cause of death only with postmortem images. (CQ15)

Pneumonia
If there is a regional invasive shadow or multiple fusion spotted invasive shadows,
there is a possibility of pneumonia. In addition, it is important to distinguish thesefindings from pulmonary blood hypostasis, lung congestion and pulmonary edema.
You should not assume pneumonia as the cause of death only with an image. (CQ16)
About each finding, it should be referred to CQ6 -9, CQ15 -16.
It is necessary to examine carefully whether you exclude external fatal causes.
We always have to take it into consideration that there are functional diseases orpoisonings that are impossible to determine only by postmortem images.
PubMed and search using the keyword postmortem.
Reference
1. Bedford PJ. Routine CT scan combined with preliminary examination as a new
method in determining the need for autopsy. Forensic Sci Med Pathol 8(4):390-4,
2012（level Ⅳ）
2. Filograna L, et al: The role of post-mortem imaging in a case of sudden death due
to ascending aorta aneurysm rupture. Forensic Sci Int 10;228(1-3):e76-80, 2013(level Ⅴ)

CQ7 What are positive findings to diagnose injuries in postmortem imaging?
Grade of recommendation: C2
There are two positive findings to diagnose injuries, which are findings from insideof the body created by external forces and findings of the objects which produced theexternal force.
Contusions of organs, deformity or translocation of organs/bones indicate damage tothe body affected by an external force. Presence of ectopic liquids like bloodindicates that the liquids have been translocated by the external force, bleeding.
Presence of ectopic gas/air indicates that the gas/air have been translocated in the
body by an external force or that the gas/air has penetrated into the body throughthe area of injury. If there are foreign objects, fragments of sharp or blunt objects, orbullets in the body, they are objects which penetrated the body.
Additionally, caution is needed since signs of fatal damage to the organs can beoverlooked in postmortem CT scans.
Explanation
Definition of injury
An injury (or wound) can be explained as damage to the human body due to theapplication of mechanical force. A weapon is defined as an object which produces aninjury.
Mechanism of injury is explained as how the injury has been produced.
It is important to determine the presence of injuries from the standpoint of forensic
medicine.
Useful CT findings to diagnose injuries
It is known that positive agreement rates between antemortem and postmortem CT
findings are high since CT scan findings of injuries are less affected by thepostmortem interval (1).
Findings of damage in the body effected by an external force: fractures of the bones,
contusions of the organs, deformity or translocation of organs/bones
While CT images are useful in diagnosing fractures of bones (3), humeral fractures
are likely to be missed when they are outside the parameters of the scan (upper
extremity and below the knee) (Fig. 1) (3). Further, CT images are also useful in thecase of road traffic accidents in which the manner of death is clearly establishedbased on the circumstances of the case, but the mechanism and the exact cause ofdeath cannot be ascertained based on external inspection (4). Although the mostcommonly injured organ is the liver in blunt abdominal trauma (5), life-threatening
liver laceration may be missed by CT scans (6). Injuries which are difficult to detect
by CT scans are bleeding in soft tissue, splenic laceration, thyroid contusion,
mesenteric lacerations, and others (2,3).
Presence of ectopic liquids/gas translocated by external forces: blood (bleedings), gas
The following are regarded as characteristic changes of a pericardial rupture after
a blunt trauma to the chest: focal pericardial dimpling and discontinuity,pneumopericardium, interposition of a lung between: aorta and pulmonary artery;or heart and diaphragm; or right atrium and right ventricular outflow tract.
Characteristic changes for a cardiac herniation include: "Empty pericardial sac"signs, air outlining the empty pleuropericardium as a result of cardiac luxution into
the hemithorax (7).
Postmortem CT scans can be a useful tool to detect the gas in the abdominal cavity,
emphysema or intramuscular bleeding which may be missed by an autopsy (2,7). In
the case of traumatic pulmonary air embolisms, the cause of death as determined bypost-mortem CT scans may differ from the autopsy based determination of thecause of death (2).
Findings of air penetrated into the body through the area of injury: gas/air pattern
In the case of stab wounds, the stab channel may be clearly visible due to the influxof air (8).
Foreign bodies penetrating the body: sharp objects, blunt objects, or bullets
In the case of impalement injuries (defined as the penetration of an elongated object
into the human body), the perforating foreign body may be displayed on the image(Fig. 2) (9). In the case of gunshot injuries, foreign objects such as bullets or metalfragments may be detected, something which helps to diagnose old gunshot injuries(10). The entrance and exit wounds of a gunshot can be detected even in the case of

badly destroyed bodies (due to fire) (2). Postmortem CT scans will be essential in theexamination of ballistic trauma (2).

Reference
1. Scholing M, et al: The value of postmortem computed tomography as analternative for autopsy in trauma victims: a systematic review. EurRadiol19(10):2333–41, 2009 （levelⅤ）
2. Andenmatten M, et al: Gunshot injuries detected by post-mortem multislice
computed tomography (MSCT): a feasibility study. Leg Med (Tokyo) 10(6):287–92,
2008 （levelⅤ）
3. Hoey B, et al: Postmortem computed tomography, ‘CATopsy’, predicts cause ofdeath in trauma patients. J Trauma 63(5):979–85, 2007 （levelⅤ）
4. Ruder TD, et al: One small scan for radiology, one giant leap for forensic medicine- Post-mortem imaging replaces forensic autopsy in a case of traumatic aortic
laceration. Leg Med (Tokyo) 13(1):41–3, 2011 （levelⅤ）
5. Christe A, et al: Abdominal trauma-sensitivity and specificity of postmortem
noncontrast imaging findings compared with autopsy findings. J Trauma
66(5):1302–7, 2009 （levelⅤ）
6. Sochor MR, et al: Postmortem computed tomography as an adjunct to autopsy for
analyzing fatal motor vehicle crash injuries: results of a pilot study. J Trauma
65(3):659–65, 2008 （levelⅤ）
7. Sherren PB, et al: Blunt traumatic pericardial rupture and cardiac herniation
with a penetrating twist: two case reports. Scand. J Trauma Resusc Emerg Med
17:64 2009 （levelⅤ）
8. Germerott T, et al: Fatal thoracic impalement on postmortem imaging. Leg Med(Tokyo) 13(2):83–6, 2011 （levelⅤ）
9. Schnider J, et al: Injuries due to sharp trauma detected by post-mortem
multislice computed tomography (MSCT): a feasibility study. Leg Med (Tokyo)
11(1):4–9, 2009 （levelⅤ）
10. Ampanozi G, et al: Incidental occult gunshot wound detected by postmortem
computed tomography. Forensic Sci Med Pathol 9(1):68–72, 2012 （levelⅤ）

Figurea case of a road traffic accident (runover)

Fracture of the left humerus and the ribs indicate a strong power (pressure orcontusion) from the left side. The axial image of the chest (A) displays the rightpneumothorax, left hemopneumothorax, emphysema in the left side chest wall
muscle, gas patterns in both ventricles, and the dislocation of the heart to the left
thoracic cavity. The 3D volume rendered image (B) shows an obvious deformity of
the left upper limb and the thorax, which indicate the direction of the external
power.

Figurea case of impalement injury

The 3D volume rendered images (A, B) display a rebar perforating the body fromthe left front to the back of the chest and fractures to the head (the facial bone andthe skull). There are gas patterns and a subarachnoid hemorrhage in the cranial
cavity (C). The 3D image of the skull base (D) shows a longitudinal fracture of theskull base from the left front to the right back of the skull base and a ring shaped
fracture around the foramen magnum (▴)

CQ8 Which postmortem image findings are useful for evaluating cervical spine
injuries?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
The postmortem CT findings of cervical spine injuries include cervical spine
fractures, dislocations, and edema and hematomas around the cervical spine.
Postmortem MRI scans may show injuries to the spinal cord, intervertebral disks,and spinal ligaments. These findings are in principle the same as those of cervicalspine injuries on antemortem images. However, care is needed with regard to one
issue specific to postmortem images: it is difficult to determine whether the trauma
occurred before or after death, even when a cervical spine injury is determined. In
addition, atlantoaxial rotatory fixation may be over-diagnosed due to abnormal
positioning of the spine in rigor mortis.
Explanation
Definition of cervical spine injuries
Cervical spine injuries result from direct/indirect trauma to the cervical spine, andcan include cervical fractures, dislocation, and intervertebral disk injuries. It iscaused by movements that exceed the normal range of cervical motion, such as
overextension, overflexion, rotation, compression, and extension that may occur intraffic accidents or in falls from great heights (Figs 1, 2). Cervical spine injuries areclassified as upper (C1–2) and lower (C5–7), and are commonly accompanied byinjuries to the spinal cord (Fig. 3). Extensive injuries to the spinal cord above the C4level may result in death.
External and internal findings for cervical spine injuries
External findings such as cervical edema are sometimes apparent, but intensive
internal injuries may occur even in the absence of obvious external findings, and it
is important not to overlook a cervical injury when there is damage to the head andface. Cervical injuries can be difficult to determine because of rigor mortis; however,an abnormal range of movement is highly suggestive of injury to the cervical spineand spinal cord (2). Hematomas may be caused to various extents by fractures or
injuries to the intervertebral disks and spinal ligaments, among other causes.
Injuries to the cervical spinal cord cause cervical swelling due to edema andhematomas, and rupture of the spinal cord is often accompanied by intensive
injuries.
Selecting the appropriate modality: chest X-ray, CT, or MRI scans
Technological developments in CT scanning have enabled the production of sagittal
multi-planar reconstructions with minimal image deterioration. In cases wherecervical spinal injuries are strongly suspected, CT scans are superior to chest X-rays
for establishing the presence of cervical spinal injuries such as fractures anddislocations (3). Thin-slice CT scans are ideal for this purpose; when many slices are
obtained, images reconstructed at a thickness of 3 mm are useful for the diagnosis (4).
With MRI scans, lesions can be detected in the cervical spinal cord, intervertebral
disks, and spinal ligaments, and it is possible to diagnose injuries to the cervicalspine (including fractures and damage to the spinal cord). With MRI scans it is also
possible to depict edema and hematomas resulting from cervical spinal cord
injuries; however, the ability of MRI scans to detect cervical spine fractures is only
similar to that of plain X-ray images, as reported in a previous study of antemortem
imaging (5). So, CT scans are therefore superior to MRI for detecting fracture lines
and small bone fragments. Still, as many reports have indicated the usefulness of
MRI for detecting injuries to the cervical spinal cord (6)-(8), postmortem MRI scansshould be provided where possible.
Existing knowledge of image features of cervical spine injuries on postmortem CT
and MRI scans
Previous reports of postmortem CT scanning have described the following featuresof cervical spine injuries: cervical spine fractures, dislocation, and edema andhematomas around the cervical spine (6)-(11). It is considered that fractures are moreeasily identified on CT scans than at an autopsy, whereas dislocation is moredifficult to identify on CT scans than with an autopsy (6). In addition, postmortem
MRI scans have been reported to enable visualization of injuries to the cervicalspinal cord, intervertebral disks, and spinal ligaments (6)-(8).
In antemortem images, the term “spinal cord injury without radiographic
abnormalities (SCIWORA) syndrome” is used if no abnormalities are apparent on
CT scans, despite intensive trauma that has caused clinical cervical spinal cord
injuries (12). As similar instances have been reported in postmortem imaging (6)(9), it
is necessary to be aware that the possibility of spinal cord injuries cannot becompletely ruled out even if there are no apparent significant abnormal findings.

A problem specific to postmortem imaging here is that in the absence of obvious
hematomas, it is often difficult to tell whether the trauma occurred before or after
death, even if cervical spine fracture is identified on CT scans (9). Here, MRI scans
are potentially superior to CT scans, because MRI scans may depict edema andhematomas, and further studies are necessary to clarify this point. Another issue isthat atlantoaxial rotatory fixation is sometimes over-diagnosed due to abnormal
body positions arising from rigor mortis (10).
Discussion
The usefulness of postmortem MRI scans has been reported for cervical spine
injuries (7)(10)(12). However, very few institutions in Japan can perform postmortem
MRI scanning. When it is necessary to perform investigations using postmortem CT
scans only, it is important to take great care in evaluating these images. In cases ofsuspected cervical spine injuries, multiplanar images reconstructed fromhigh-resolution CT scans are used to identify possible cervical fracture lines,
deformation, and ossicles. The mechanism of trauma can be inferred based on the
distribution of fractures and the presence of dislocations; therefore, it is important
to assume that injuries to the upper cervical spinal cord could have been the causeof a fatality. Because there may be “spinal cord injuries without radiographic
abnormalities”, it is necessary to seek to identify surrounding hematomas andswelling of the soft tissue as well as fractures and dislocations, as these findings willassist in determining the mechanism of the trauma. Common and possible types ofcervical spine injuries and pathologies, which must be differentiated, are listed
below.
Common types of cervical spine injuries
At the craniovertebral junction (C1–2)



Atlantooccipital dislocations

Fractures of the atlas (posterior arch fractures, fractures of lateral masses of
the atlas, Jefferson fractures)Axis fractures (odontoid fractures, Hangman’s fractures, extension tear-drop
fractures)Atlantoaxial subluxation

Atlantoaxial rotatory fixations

At the lower cervical spine (C5–7)



Hyperflexion injuries (ligament injuries, compression fractures, flexion
tear-drop fractures, bilateral locked facets, clay-shoveler’s fractures)Hyperflexion rotator injuries (unilateral locked facets)Hyperextension injuries (extension tear-drop fractures, retrospondylolisthesis,
endplate avulsion fractures and intervertebral enlargement, anterior vertebral
soft tissue swellings)

Pathologies to be differentiated from cervical spine injuries
Normal variations (including os odontoideum), congenital anomalies (including
spina bifida, assimilation vertebra), spur formation/transformations due to cervicalspondylosis, ossification of the posterior longitudinal ligament
Key words
Postmortem, CT, MRI, cervical spine
References
1. Hatori K: Injury. In: Ishizu H, Takatsu M, editor. Hyojun Houigaku 7 th edition,
p67, Igaku Shoin, Tokyo, 2013 (Level N/A）
2. Ishobe I: Other injury. In: Takatori T, editor. New essential Houigaku 5th edition,
p148-149, 2012 (Level N/A）
3. Holmes JF, Akkinepalli R: Computed tomography versus plain radiography toscreen for cervical spine injury: a meta-analysis. J Trauma 58: 902-905, 2005 (Level
3)
4. Phal PM et al: Fracture detection in the cervical spine with multidetector CT:
1-mm versus 3-mm axial images. AJNR 29: 1446-1449, 2008 (Level 4)
5. Katzberg RW et al: Acute cervical spine injuries: prospective MR imaging
assessment at a level 1 trauma center. Radiology 213: 203-212, 1999 (Level 5)
6. Yen Y et al: Postmortem multislice computed tomography and magnetic
resonance imaging of odontoid fractures, atlantoaxial distractions and ascending
medullary edema. Int J Legal Med 119: 129-136, 2005 (Level 5)
7. Okuda T et al: A case of fatal cervical diskoligamentous hyperextension injury
without fracture: Correlation of postmortem imaging and autopsy findings. Forensic
Sci Int 225: 71-74, 2013 (Level 5)
8. Stäbler A et al: Cervical spine: postmortem assessment of accident injuries –comparison of radiographic, MR imaging, anatomic, and pathologic findings.

Radiology 221: 340-346, 2001 (Level 5)
9. Iwase H et al: Can cervical spine injury be correctly diagnosed by postmortem
computed tomography? Leg Med (Tokyo) 11: 168-174, 2009 (Level 5)
10. Persson A et al: Atlanto-axial rotatory subluxations in postmortem CT:
radiologists be aware of a common pitfall. Forensic Sci Int 225: 9-14, 2013
11. Uhrenholt L, Boel LW: Contributions from forensic imaging to the investigationof upper cervical fractures. J Forensic Sci 55: 1598-1602, 2010
12. Kasimatis GB et al: The adult spinal cord injury without radiographic
abnormalities syndrome: magnetic resonance imaging and clinical findings inadults with spinal cord injuries having normal radiographs and computed
tomography studies. J Trauma 65: 86-93, 2008 (Level 5)

FigureCervical spine injury (1)The individual was discovered after being crushed by a tractor; however, there wasno compression injuries to the trunk, and no obvious trauma to the surface of thebody.
The axial CT image (A) depicts dislocation of the atlantoaxial joint. Sagittal images(B, C) indicate cervical spinal cord injuries due to compression by the dens axis.

Figurecervical spine injury (2)The individual was discovered leaning over a fence, with cervical overextension.
The autopsy showed no abnormal posture or apparent external trauma. The CT
scanning was performed with the neck in flexion (A) and extension (B). The sagittal
images depict a small bone fragment at the upper levels of C4 and C6 (▲). The
anterior C5-6 intervertebral space is wide open in the extension position. It isdifficult to tell whether there is surrounding hematomas. A 3D reconstruction (C)depicts the fragmented ossicles (▲) but details are unclear.

Figurecervical spine and spinal cord injury

Apparently this individual had rolled down stairs from the second floor. There was acontused laceration on the forehead.
Injury to the intervertebral disks and spinal cord cannot be evaluated on thesagittal CT scan of the cervical spine, although small ossicles (▲) can be identified
ventrally at the C3-4 and C5-6 levels (A). The MRI scan of the cervical spine(sagittal T2 weighted image) shows hematomas (▲) and spinal cord injuries at thelevel of C3-4 (→) (B). The sagittal fat-suppressed T2 weighted image depicts two
high-intensity lesions (isointense to cerebrospinal fluid) at the anterior border of theintervertebral disks at the C3-4 and C6-7 levels (▲), suggestive of intervertebral
disk injuries (C). The axial T2* weighted image shows patchy areas of low intensity
in the spinal cord at the level of C3-4, suggestive of hematomas (D). The photographshows hematomas anterior to the cervical spine during dissection of the cervicaltrachea (E). There are enlarged intervertebral spaces (▲) at the C3-4 and C6-7
levels (F). Ecchymosis is identified in the central gray matter at the level of C3-4 on
an axial slice after fixation of the cervical spinal cord (G).

CQ9 Can unenhanced postmortem CT scans help diagnose an acute coronary
syndrome as a cause of death?
Grade of recommendation: D
Unenhanced postmortem CT scans cannot delineate thromboembolisms of thecoronary artery or ischemic myocardium; therefore, it cannot provide definitive
information to diagnose acute myocardial infarction or ischemic sudden cardiac
death.
Explanation
Acute coronary syndrome
The term “acute coronary syndrome” comprehensively includes three pathologic
states: unstable angina, acute myocardial infarction, and ischemic sudden cardiac
death. Sudden cardiac death refers to sudden death due to cardiac diseases andinvolves acute myocardial infarction, fatal arrhythmia, cardiomyopathy, cardiac
sarcoidosis, myocarditis, and others.
Unenhanced postmortem CT scans
In clinical practice, modalities to diagnose angina, myocardial infarction, andarrhythmia include ECG, ultrasound, coronary angiography, enhanced CT scans,
cardiac MRI images (with or without contrast media), and cardiac nuclear imaging.
However, after death, these modalities are not practical or at least not part ofstandard methods (1-6). In Japan, unenhanced postmortem CT scans are commonlyused in screening examinations to determine causes of unusual death (3-6). However,unenhanced postmortem CT scans cannot identify direct findings of acute
myocardial infarctions or ischemic sudden cardiac death cases (such as coronary
arterial thromboembolism and ischemic myocardium), although they can assist in
detecting fatal hemorrhagic lesions (such as cerebral hemorrhages, subarachnoid
hemorrhages, aortic dissections, or aortic aneurysmal ruptures) (1-6).
Pulmonary edema on postmortem CT scans
Ischemic heart disease is suspected in patients who are transferred to emergency
hospitals in a state of cardiopulmonary arrest on arrival and confirmed dead after
undergoing cardiopulmonary resuscitation, in combination with clinical information(such as acute chest pain before death), the patient’s past medical history (such asdiagnosed with angina or old myocardial infarctions), examination findings (such asabnormal ECG findings), and indirect postmortem CT findings (such as pulmonary
edema, calcification of the coronary artery, or a markedly enlarged / hypertrophic
heart) (3-5). In such sudden death cases with known clinical histories that lead todeath, the presence of pulmonary edema due to acute left heart failure can be an
indirect image finding of ischemic heart disease. However, pulmonary edema is a
non-specific finding that may occur due to extrinsic factors (such as drugs or
suffocation), and it would be difficult to differentiate it from similar CT scandensities other than pulmonary edema (such as infiltrative shadows due topneumonia), and pulmonary edema occurring immediately before death may bemasked by postmortem pulmonary edema that appears with time after death (7,8).
Therefore, the presence of pulmonary edema should not be simply interpreted as
the presence of ischemic heart disease in cases where the circumstances at the timeof death or the clinical history that lead to death is unknown.
On postmortem CT images, band-like shadows are often seen along the pleura in
the dependent portion of the lungs. This is the so-called postmortem hypostasis of
the lung (3). It appears on the dorsal side of the body if lying / laid in the supine
position after death, while it appears on the ventral side if lying in the prone
position after death.
Reference
1. Weusink AC, et al: Minimally invasive autopsy: an alternative to conventional
autopsy? Radiology 250:897-904, 2009 （levelⅤ）
2. Robert ISD, et al: Post-mortem imaging as an alternative to autopsy in the
diagnosis of adult deaths: a validation study. Lancet 379:136-42, 2012 （levelⅣ）
3. Shiotani S, et al: Non-traumatic postmortem computed tomographic (PMCT)
findings of the lung. Forensic Sci Int 139:39-48, 2004 （levelⅤ）
4. Kaneko T, et al: Postmortem computed tomography is an informative approachfor prevention of sudden unexpected natural death in the elderly. Risk Managementand Healthcare Policy 3:13-20, 2010 （levelⅤ）
5. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22:152-160, 2012 （levelⅤ）
6. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: a review of 339 forensic cases. Leg Med (Tokyo)
14:239-45, 2012 （levelⅣ）

7. Shiotani S, et al: Postmortem pulmonary edema: a comparison between
immediate and delayed postmortem computed tomography. Legal Med (Tokyo)
13:151-5, 2011 （levelⅤ）
8. Michiue T, et al: Quantitative analysis of pulmonary pathophysiology using
postmortem computed tomography with regard to the cause of death. Forensic Sci
Int 220:232-8, 2012 （levelⅤ）

CQ10 What are the best modalities for and acceptable findings to detect acutecoronary syndrome on postmortem images?
Grade of recommendation: C2
Postmortem CT angiography (CTA) of the coronary artery has been reported toshow coronary arterial thromboembolisms as a filling defect, which cannot bedelineated by unenhanced CT scans. Postmortem cardiac MRI scanning has beenreported to show ischemic myocardium as abnormal signal intensities, which also
cannot be delineated by unenhanced CT scans.
Explanation
Acute coronary syndrome (Refer to CQ9)
The term “acute coronary syndrome” comprises three pathologic states that occur
due to sudden stenosis of the coronary artery: unstable angina, acute myocardial
infarction, and ischemic sudden cardiac death (1). Unenhanced postmortem CT scanscannot directly show findings of acute myocardial infarction or ischemic sudden
cardiac death cases (including coronary arterial thromboembolism and ischemic
myocardium). Postmortem CTA of the coronary artery and cardiac MRI scans havebeen reported to show these pathologic states (2,3).
Postmortem CTA of the coronary artery
Postmortem CTA of the coronary artery is performed mainly to detect
thromboembolisms. Three different methods have been reported:
Method of the Virtopsy Group in Europe (4,5):
Based on an embalming technique, cannulation is performed in the femoral arteryand femoral vein, contrast media are infused from the artery, and blood is collectedfrom the vein to generate circulation using an artificial heart lung apparatus.
Angiographic images of the entire body including the coronary artery can beobtained in this manner. Surgical techniques are required in such cases.
Method of the University of Leicester, England (6)A urethral balloon catheter is inserted from the internal carotid artery, and theballoon is inflated at the proximal portion of the ascending aorta; then, contrast
media are infused from the catheter. This method is simpler than that of the
Virtopsy Group above (1), and enhanced images of the coronary artery are obtained.

Surgical techniques are also required in such cases.
Method of the Tokyo Medical Center (7)Chest compression is performed while infusing contrast media via the peripheral
venous route which is retained at the time of cardiopulmonary resuscitation in an
emergency room. This method is simpler than those of the Virtopsy Group (1) andthe University of Leicester (2), and no surgical techniques are mandatory; however,
the ability to show the coronary artery is generally inferior to those of the other two
methods.
Cardiac MRI
Postmortem cardiac MRI is conducted for the purpose of identifying ischemic
myocardium. Pathological alterations due to myocardial infarction appears
microscopically a few hours after the onset of myocardial infarction, andmacroscopically at 6 to 12 hours. A pathological diagnosis is very difficult inischemic sudden cardiac cases of death within a few minutes to one hour after the
onset of the disease. A postmortem cardiac MRI scan can differentiate ischemic
myocardium of the hyperacute phase from the acute phase, the subacute phase, andthe chronic phase. With T2-weighted images on the postmortem cardiac MRI
ischemic myocardium of the hyperacute phase is delineated as a low signal intensity
area (7). The reasons for the low signal intensity are considered to be due to acidosisof the ischemic myocardium or reduced arterial blood flow while venous circulationis still maintained. Approximately 3 hours after coronary artery occlusion,
myocardial edema appears due to ischemia and re-perfusion injuries. Here,ischemic myocardium of the acute phase is delineated as a high signal intensity
area on T2-weighted images (Figure) (8-10).
Note that when examining the heart by MRI, scan sequences should be determined
to optimize scans of the heart, not for the entire chest region.
Reference
1.

Saukko P, et al: The pathology of sudden death. In: Saukko P, Knight B, eds.

Knight’s Forensic Pathology. 3rd ed. London UK: Hodder Arnold.492-526, 2004
2. Morgan B, et al: Postmortem computed tomography (PMCT) scanning with
angiography (PMCTA): a description of three distinct methods. In: Rutty GN ed.
Essentials of autopsy practice. 1st ed. London UK: Springer 1-21, 2014

3. Ruder TD, et al: Essentials of forensic post-mortem MR imaging in adults. Br J
Radiol Epub ahead of print 4, 2013
4. Ross SG, et al: Sudden death after chest pain: feasibility of virtual autopsy with
postmortem CT angiography and biopsy. Radiology 264:250-9, 2012 （levelⅤ）
5. Michaud K, et al: Postmortem imaging of sudden cardiac death. Int J Legal Med
128:127-37, 2014 （levelⅤ）
6. Saunders SL, et al: Targeted post-mortem computed tomography cardiac
angiography: proof of concept. Int J Legal Med 125:609-16, 2011 （levelⅤ）
7. Iizuka K, et al: Feasibility of resuscitation contrast-enhanced postmortem computed
tomography using cardiopulmonary resuscitation technique with chest compression
immediately after death. SpringerPlus 2:1-5, 2013 （levelⅤ）
8. Jackowski C, et al: Post-mortem cardiac 3-T magnetic resonance imaging:visualization of sudden cardiac death? J Am Coll Cardiol 62:617-29, 2013 （levelⅤ）
9. Shiotani S, et al: Postmortem magnetic resonance imaging (PMMRI) demonstrationof reversible injury phase myocardium in a case of sudden death from acute coronary
plaque change. Radiat Med 23:563-5, 2005 （levelⅤ）
10. Ruder TD, et al: Edema is a sign of early acute myocardial infarction on
post-mortem magnetic resonance imaging. Forensic Sci Med Pathol 9:501-5, 2013（levelⅤ）

FigureA case of suspected catecholamine cardiomyopathy due to burn injuries of the wholebody.

This individual died after severe burn injuries. On the postmortem cardiac MRI(short axis T2-weighted image at the level of the midventricular level, A), mottled
high signal intensities can be seen in the entire circumference of the left ventricle.
This high signal intensity extends to the right ventricular wall. The macroscopic
view of a coronal section of the heart (B) shows scattered whitish-colored portions(which histologically correspond to fibrosis) in the left ventricular wall, but nolesions that correspond to the mottled high signal intensities on the MRI can be
identified.

CQ11 Can postmortem CT scans be used to diagnose pericardial hematomas?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
Pericardial hematomas can be diagnosed as the cause of death when a high density
band is surrounding the myocardium at the pericardium. More than 200 ml of a
pericardial hematoma may be considered to be a cause of death. Postmortem
procedures, such as cardiopulmonary resuscitation, cardiac centesis, may affectpostmortem pericardial hemorrhages.
Explanation
Discussion
A pericardial hematoma is the condition of hematomas of the surrounding
pericardial space. When the pericardial space contains material, the pericardial
space pressure increases, cardiac dilatation becomes constrained, and cardiac
failure may occur. This is the so-called cardiac tamponade.
Cardiac tamponade may occur for a number of reasons, due to contained serum
fluid (from cardiac failure), fibrosis (infection, connective tissue diseases, uremia),and hematomas (malignancies, infections, some cause of basic bleeding, trauma, for
idiopathic reasons) at the pericardial space.
A pericardial hematoma is thought to rupture from the aortic wall or myocardialwall into the pericardial lumen, which causes blood to leak into the pericardium.
The pericardial hematoma restricts the cardiac atrial / ventricular motion, andincreases the pericardial pressure above that in the cardiac dilatation phase,resulting in circulatory malfunction leading to death.
Pericardial hematoma image
According to published data, more than 200 ml of pericardial hematoma is likely tolead to circulatory failure, and this may further develop to become the cause ofdeath. When the growth of a pericardial hematoma is rapid, less than 100 ml of
pericardial hematoma may cause death. According to autopsy reports, pericardialhematomas have reached 300 – 400 ml or more. When the physician makes a causeof death diagnosis, the pericardial hematoma volume should not be used as a sole
reason.
Shiotani et al. reported that a 60 % acute aortic dissection case collection presented

a pericardial high density area (blood cells) with a relatively lower density area
(blood plasma), and the appearance of pericardial hematomas has been termed“hyperdense armored heart (HAH)”.

At HAH the cardiac beat continued during

the bleeding into the pericardial space, and the blood in the inner pericardial spacecaused fibrinization (outer pericardial space blood showed de-fibrinization), so thatthe pericardial hematoma restricted the cardiac motion leading to this being thecause of death. In animal experiments, a pericardial hematoma could not bedemonstrated in a sudden death model. When the pericardial hematoma is present
in postmortem CT scans, it may be difficult to distinguish the pericardial hematoma
or pericardial blood contained; when the blood leakage started before theante-mortem period, this may show it to be a real pericardial hematoma; however,when the blood leakage started after the post-mortem period, it may indicate
leakage of the postmortem liquefied blood into the pericardium. Distinguishing
between pericardial hematomas and pericardial blood by the appearance of leaked
blood on postmortem CT scans may be difficult.
Other findings about pericardial hematomas (cardiac tamponade) have reported
venousdilatation(IVC,

hepatic

vein,

renal

vein),

decreasing

cardiacanterior-posterior distance, and cardiac septal deviation. When findings like thoseare identified along with the HAH, the cause of death may be cardiac
hemo-tamponade (hematoma).
The pericardial volume measurement shows a high correlation with actual
measurements (CQ23).
Differential diagnosis
1. Cardiac rupture due to myocardial infarction
2. Dissecting aortic aneurysm pericardial space rupture
3. Cardiovascular rupture due to trauma
4. Cardiovascular rupture due to CPR
5. Blood leakage due to postmortem needle insertion
6. Rare pathologies; myocarditis, coronary artery aneurysm, pulmonary artery
dissection, iatorogenic (IR procedure)Reference
1. Filograna L, et al: The role of post-mortem CT (PMCT) imaging in the diagnosis of
pericardial tamponade due to hemopericardium: A case report. Lega Med 16:150-3, 2014（levelV）
2. Forauer AR, et al: Pericardialtamponade complicating central venous interventions. J
Vasc Interv Radiol 14:255-9, 2003 (levelⅤ)
3. Karger B, et al: Physical activity following fatal injury from sharp pointed weapons.
Int J Legal Med 112:188-91, 1999 (levelⅣ)
4. Shiotani S, et al: Postmortem computed tomographic (PMCT) findings of pericardial
effusion due to acute aortic dissection. Radiat Med 22:405-7, 2004 (levelⅣ)
5. Hori S，et al. Why is pericardio-centesis possible in acute hemopericardium? Igaku
No
Ayumi 139: 353-4, 1986 （levelⅣ）
6. Krejci CS, et al: Hemopericardium: an emergent finding in a case of blunt cardiac
injury. Am J Roentgen 175:25, 2000 (levelⅤ)
7. Oyama N, et al: Computed tomography and magnetic resonance imaging of the
pericardium: anatomy and pathology. Magn Reson Med Sci 3:145–52, 2004 (levelⅤ)
8. Rotondo A, et al: Periportal lymphatic distension resulting from cardiac tamponade:CT findings and clinical-pathologic correlation. Emerg Radiol 6:85–93, 1999 (levelⅤ)
9. Hernandez-Luyando L, et al: Tension pericardial collections: sign of ‘‘flattened heart’’in CT. Eur J Radiol 23:250–2, 1996 (levelⅤ)
10. Doppman JL, et al: Computed tomography in constrictive pericardial disease. J
Comput Assist Tomogr 5:1–11, 1981 (levelⅤ)
11. Chong HH, et al: Pericardial effusion and tamponade: evaluation, imaging
modalities, and management. Compr Ther 21:378–85, 1995 (levelⅥ)
12. Ebert LC, et al: CT based volume measurement and estimaton in cases of
pericardial effusion. J Forensic Leg Med 19:126-31, 2012 (levelⅣ)

FigureHemo-cardiac tamponade due to dissecting aneurysmal rupture

The cadaver was discovered in the driver seat. There is no motor vehicle damage.
On the postmortem CT scan, there is a double band hemo-pericardium withcollapsing ascending aorta. The amount of hemo-pericardium is about 425 ml by CT
volumetry. At the autopsy, pericardial coagulation is demonstrated whichsurrounding myocardium (the so called “armored heart”). An internal tear is
detected at the ascending aorta. The cause of death was reported to be of the
DeBakey type II, and aortic dissection led to pericardial rupture causing thehemo-pericardium.

FigureMyocardial infraction, pericardial hematoma due to anterior wall rupture

The cadaver was discovered on the sidewalk of a road. After ER admission, death
was confirmed. Superficial abrasions were found at the face and fingers. The
postmortem CT presented pericardial high and low density areas, with a total
volume of 398.0 ml. A pericardial hematoma surrounding the myocardium, wasconfirmed at the autopsy. The left ventricular anterior wall presented discolorationand dehiscence. The left coronary artery was occluded at the origin of the left
anterior, descending. A myocardial infarction was demonstrated at the left anterior
to the septal wall with thinning and dehiscence.

CQ12 Can postmortem CT scans detect subarachnoid hemorrhages as a cause ofdeath?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
A fatal subarachnoid hemorrhage is strongly suggested when postmortem CT scansshow a subarachnoid hemorrhage concentrated at the base of the brain,accompanying intraventricular hemorrhage, or accompanying lung edema.
Explanation
Usefulness of CT scans in the detection of subarachnoid hemorrhages (1-5)
The usefulness of CT scans in the detection of subarachnoid hemorrhages has beenclinically established. On unenhanced CT images, a subarachnoid hemorrhage isdelineated as a high-density area in the subarachnoid space or cistern; this makes
detection straightforward (Figure 1).
Scanning conditions of postmortem CT images to detect intracranial lesions (6)The conventional CT scan mode has been reported to be better for the detection of
intracranial lesions than the helical scan mode in postmortem CT scanning.
Conventional scanning parameters with a slice thickness of 5 mm are considered
suitable for acquiring postmortem CT images of the head region.
Comparison between postmortem CT scans and autopsy findings of subarachnoid
hemorrhages (7-11)
Subarachnoid hemorrhages on postmortem CT scans has been reported to bepathologically confirmed by autopsies in radiologic-pathologic correlation studies(Figure 2).
Characteristic findings in subarachnoid hemorrhage cases involving death before
arrival at a hospital (12-14)
About 3 to 17% of subarachnoid hemorrhage patients die before arriving at a
hospital. Frequently observed findings in such cases include intraventricularhemorrhage, pulmonary edema, and aneurysmal rupture of the vertebrobasilar
artery. Therefore, subarachnoid hemorrhage is strongly suggested as a cause ofdeath when postmortem CT scans show a subarachnoid hemorrhage concentrated

at the base of the brain, accompanying intraventricular hemorrhage, or lung edema.
Differentiation of traumatic and non-traumatic subarachnoid hemorrhages (15-21)
In most cases, it is clinically possible to differentiate traumatic from non-traumatic
subarachnoid hemorrhages associated with the rupture of an aneurysm based on
CT findings of the distribution of hematomas or cerebral contusion due to a
traumatic injury. However, careful diagnosis should be performed, as exceptions
have been reported.
Note that differentiation between traumatic and non-traumatic subarachnoid
hemorrhages is difficult in cases of head or neck injuries including mild injuries
involving damage to the vertebral or basilar artery (such as from sports
activity-related injuries accompanying contusions to the face, jaw, or neck, andtorsion of the neck), which induces a widespread subarachnoid hemorrhage in thebasal cistern.
Reference
1. Connolly ES, et al： Guidelines for the management of aneurismal subarachnoid
hemorrhage: a guideline for healthcare professionals from the American heart
association/American stroke association. Stroke 43 2012 （levelⅠ）
2. Black M, et al: Sudden unexpected death in adults caused by intracranial
pathology. J Clin Pahtol 55: 44-50, 2002 （levelⅤ）
3. Gijn JV, et al: Subarachnoid haemorrhage: diagnosis, causes and management.
Brain,124:249-78, 2001 （levelⅤ）
4. Edirisinghe PAS:Subarachnoid haemorrhage as a cause of death: a review offorensic autopsies conducted in Edinburgh. Sri Lanka Journal of Forensic Medicine,
Science & Law 1:14-9, 2010 （levelⅣ）
5. Lemonick DM:Subarachnoid hemorrhage: state of the art(ery). American Journalof Clinical Medicine 7:62-73, 2010 （levelⅤ）
6. Daly B, et al: Sensitivity of conventional head CT compared with helical head CT
for intracranial findings during whole body imaging autopsy in a U.S. state medical
examiner’s investigation of sudden death. RSNA, scientific assembly and annual
meeting program 977, 2008 （levelⅣ）
7. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14:239-45, 2012 （levelⅤ）

8. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22:152-60, 2012 （levelⅤ）
9. Cha JG, et al: Utility of Postmortem Autopsy via Whole-Body Imaging: Initial
Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings.
Korean J Radiol ;11:395-406, 2010 （levelⅤ）
10. Bolliger SA, et al: Postmortem imaging-guided biopsy as an adjuvant tominimally invasive autopsy with CT and postmortem angiography: a feasibility
study. AJR Am J Roentgenol 195(5):1051-6, 2010 （levelⅤ）
11.

Weustink AC, et al: Minimally invasive autopsy: an alternative to conventional

autopsy? Radiology 250(3):897-904, 2009 （levelⅤ）
12. Schevink WI, et al: Sudden death from aneurysmal subarachnoid hemorrhage.
Neurology 45: 871-4,1995 （levelⅤ）
13. Huan J, et al: The probalility of sudden death from rupture of intracranial
aneurysms: a meta-analysis. Neurosurgery 51: 1101-7, 2002 （levelⅠ）
14. Sheikhazahi A, et al: Survey of sudden death from aneurismal subarachnoid
hemorrhage in cadavers referred to Legal Medicine Organization of Tehran,
2001-2005. Am J Forensic Med Pathol 30: 358-61, 2009 （levelⅤ）
15. Contostavlos DL:Massive subarachnoid haemorrhage due to laceration of thevertebral artery associated with fracture of the transverse process of the atlas. J
Forensic Sci 16: 40-56, 1971 （levelⅤ）
16. Harland WA, et al: Subarachnoid haemorrhage due to upper cervical trauma. J
Clini Pathol 36: 1335-41,1983 （levelⅤ）
17. Dowling G, et al: Traumatic basal subarachnoid hemorrhage. Report of six cases
and review of the literature. (review). Am L Forensic Med Pathol 9: 23-31, 1988
（levelⅤ）
18. Kindelberger D, et al:Hyperextension and rotation of head causing internal
carotid artery laceration with basilar subarachnoid hematoma. J Forensic Sci 48:
1366-8, 2003 （levelⅤ）
19. Kaiser Ch, et al: Traumatic rupture of the intracranial vertebral artery due torotational acceleration. Forensic Sci Int 182:15-7, 2008 （levelⅤ）
20. Iwase H, et al： Can cervical spine injury be correctly diagnosed by postmortem
computed tomography? Leg Med (Tokyo) 11:168-74, 2009（levelⅤ）

FigureTraumatic subarachnoid hemorrhage

Axial (A) and coronal (B) postmortem CT images of the head.
Subdural hematoma, cerebral contusion of the frontal lobe, and secondary
subcortical hemorrhage can be seen, in addition to the subarachnoid hemorrhage. A
high-density fluid level is seen in the posterior horns of the bilateral ventriculi. A
subgaleal hematoma (arrowhead) is visible in the left occipital region. The autopsy
confirmed intracranial injuries due to the occipital region being hit (subdural
hematoma, cerebral contusion, and traumatic subarachnoid hemorrhage).

FigureSubarachnoid hemorrhage due to aneurysmal rupture of the right vertebral artery

A woman living by herself was discovered dead at home. Upon superficial inspection,
discoloration of the left forehead indicating old subcutaneous bleeding andhematoma of the left eyelid (black eye) were observed; an autopsy was performed forfurther investigation. The postmortem CT scans (axial image A, coronal image B)
showed a widespread subarachnoid hemorrhage predominantly at the base of thebrain. A thick hematoma is seen at the base of the resected brain (C). Afterremoving the hematoma and exposing the artery at the base of the brain (D), a
spindle-shaped aneurysm with an osculum was discovered in the right vertebral
artery, this would accompany the formation of a thrombus, histologically.

CQ13 Is it possible to diagnose cerebral hemorrhages which are causes of death?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of deathSome hematomas, which are located in the brainstem, with volumes larger than 30
cm3, with ventricular extension of blood, with ventricle compression, or withmidline shifts over 5 mm, may be strongly suspected as causes of death.
Explanation
Intracranial hemorrhages show high density on head CT scans, and it is clinically
acceptable to diagnose intracranial hemorrhage.
Postmortem head CT scan parameters
Daly et al. reported that conventional CT scans are more sensitive to major
intracranial findings than helical CT scans in decedents. Conventional head CT
scanning is suitable for evaluating postmortem examinations.
Postmortem CT scans and pathological correlation with cerebral hemorrhages
Some investigators reported cerebral hemorrhages that were diagnosed bypostmortem CT scans and which were confirmed by an autopsy. Kasahara et al.
reported that six fatal cerebral hemorrhages present on postmortem CT scans wereconfirmed in the autopsy.
Clinical fatal findings of cerebral hemorrhages on CT scans
It is reported that predictors on head CT scans of 30-day mortality rates after the
onset of intracerebral hemorrhages are 1) hematomas located in the brainstem, 2)
hematoma volumes larger than 30 cm3, 3) ventricular extension of blood, 4)ventricle compression by a hematoma, or 5) hematomas with midline shifts of morethan 5mm. Such life-threatening findings are strongly suspected as causes of death.
#: Subtle cranial fractures are difficult to detect on CT images. Postmortem
destruction should be taken into consideration.

Reference
1. Xavier AR, et al: Neuroimaging of stroke: a review. Southern Med J 96(4):367,
2003 （levelⅥ）
2. Daly B, et al: Sensitivity of conventional head CT compared with helical head CT
for intracranial findings during whole body imaging autopsy in a U.S. State Chief
Medical Examiner's investigation of sudden death. RSNA Scientific assembly andannual meeting program 977, 2008 （levelⅣ）
3. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14(5):239-45, 2012 （levelⅣ）
4. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22(1):152-60, 2012 （levelⅣ）
5. Cha JG, et al: Utility of Postmortem Autopsy via Whole-Body Imaging: Initial
Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings.
Korean J Radiol 11(4):395-406, 2010 （levelⅤ）
6. Bolliger SA, et al: Postmortem imaging-guided biopsy as an adjuvant tominimally invasive autopsy with CT and postmortem angiography: a feasibility
study. AJR Am J Roentgenol 195(5):1051-6, 2010 （levelⅤ）
7. Weustink AC, et al: Minimally invasive autopsy: an alternative to conventional
autopsy? Radiology 250(3):897-904, 2009 （levelⅤ）
8. Nilsson OG, et al: Prediction of death in patients with primary intracerebral
hemorrhage: a prospective study of a defined population. J Neurosurg 97(3):531-6,
2002 （levelⅣ）
9. Nag C, et al: Prediction of clinical outcome in acute hemorrhagic stroke from asingle CT scan on admission. North Am J Med Sci 4(10):463-7, 2012 （levelⅣ）

FigureBrainstem bleeding (postmortem about 1 month)

Because of putrefaction, air (gas) is demonstrated in the brain parenchyma. Thereis a high density at the brainstem, making the cause of death estimated to bebrainstem bleeding.

FigureRight thalamic bleeding (confirmed by autopsy)

The brain CT scan (fig. a) presented intra-cranial bleeding which penetrates into
the lateral ventricle, so that a fluid-fluid level is present at both the posterior hornsof the lateral ventricles. The bleeding (hematoma) volume was measured as 80.6 ml
on the image workstation, and 104.2 ml with intra-ventricular bleeding (highdensity volume).
Chest CT scan (fig. b) showing ground-glass opacity with bilateral pleural space
fluid collection. At the autopsy, the lung weight was 586 g for the left lung and 716 g
for the right lung. At the macroscopic investigation, the lung showed severe
edematous changes. The pleural space fluid collection is about 40 ml in the left
chest cavity and about 50 ml in the right chest cavity. Because the cadaver was
discovered at low temperature circumstances, the putrefaction changes wereminimized. The postmortem interval was estimated to be about 7 days.

CQ14 Can aortic aneurysms and aortic dissections be diagnosed as the cause ofdeath by postmortem imaging?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
Aortic ruptures caused by aortic dissection and ruptures of aortic aneurysms may
be a cause of death by inducing hemorrhagic shock and may be diagnosed bypostmortem imaging.
Diagnosis of the direct cause of death is straightforward if there is only one
pathological condition.
However, if the condition is caused by an injury, the severity of other findings
should also be assessed.
Explanation
Aortic dissection is a condition in which the inner layer of the aorta is torn andblood surges through the tear, causing the inner and middle layers of the aorta toseparate.
A Stanford A type with the lesion of the ascending aorta may be fatal if it is treatedconservatively: 20% of patients die within 24 hours of the onset, 30% within 48
hours, 40% within 1 week and 50% die within 1 month. Most of the deaths are due
to cardiac tamponade arising from the development of the hemorrhage into
pericardial space. 1-8)
Some reports have found postmortem CT scans with enhancement useful todiagnose the condition.
What findings may be identified?
The evidence of a fatal hemorrhagic lesion are: ① High-attenuation fluid collection
surrounding the aorta (a hematoma) 1-8), ② a pericardial hematoma7), ③ muralthrombosis, depiction of a false lumen, ④hemorrhagic pleural effusion,

ascites,⑤ deformity of the arterial wall, deformed aneurysms, and ⑥ rupture of aortic
aneurysm wall.

What findings may be evidence for the cause of death?
One of the six described above may be evidence.
However, a single finding of pericardial hemorrhage is sometimes difficult todifferentiate from a left ventricular rupture caused by myocardial infarction.
In other situations, hemorrhagic pleural effusion may be caused by the rupture of
the pericardium after chest oppression in cases of left ventricular rupture caused bymyocardial infarction9).
Also, rupture of abdominal aortic aneurysms may cause a hemorrhage not in theabdominal cavity but in the retroperitoneum.
What kind of imaging conditions are useful to diagnose these conditions?
Reconstructed images such as sagittal images may be useful to identify sites ofentry and re-entry of a dissection.
It is also useful to establish the site of the rupture.
Pathological conditions and diseases that must be differentiateda) Aortic aneurysm (dissection・genuine aneurysm)b) Traumatic aortic rupture (isthmus of the aorta)c) Traumatic cardiac rupture and pericardium rupture (in falls from high places)d) Multiple injuries to the thorax (lung contusion・Pneumothorax・injuries to theintercostal arteries and veins)e) Cardiac and pericardial ruptures caused by chest oppression (cardiopulmonary
resuscitation)f) Spontaneous pneumothorax and endometriosis in rare cases

Reference
1. Sakamoto N, et al: Interpretation of multi-detector computed tomography images
before dissection may allow detection of vascular anomalies: a postmortem study ofanomalous origin of the right subclavian artery and the right vertebral artery. Anat
Sci Int Aug 29, 2012 (levelV)
2. Vogt KM, et al: Fluoroscopic angiography in the gross anatomy dissection
laboratory: visualizing the aortic arch and its branches in a cadaver. Clin Anat
Mar;24(2):253-7, 2011 (levelV)
3. Ross SG, et al: Sudden death after chest pain: feasibility of virtual autopsy with
postmortem CT angiography and biopsy. Radiology 264(1)250-9, 2012 (levelV)
4. Shiotani S, et al: Non-traumatic postmortem computed tomographic (PMCT)
findings of the lung. Forensic Sci Int 6;139(1):39-48, 2004 (levelV)
5. Kasahara S,et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: a review of 339 forensic cases. Leg Med (Tokyo)
14(5):239-45, 2012 (levelV)
6. Yamazaki K, et al: Comparison between computed tomography (CT) and autopsy
findings in casesof abdominal injury and disease. Forensic Sci Int 16(162)163-6,
2006 (levelV)
7. Shiotani S, et al: Postmortem computed tomographic(PMCT) findings ofpericardial effusion due to acute aortic dissection, Radiat Med 2004;22(6):405-7,
2004 (levelV)
8. 槇野 陽介ほか：腹部大動脈瘤破裂死亡例の死後 CT 画像所見(会議録)日本医学放射線学会学術集会抄録集(0048-0428) 69回 S354-S355, 2010 (levelV)
9. Burke M, et al: Management of medicolegal natural deaths fromhemopericardium or hemothorax using postmortem CT scanning, Forensic Sci Med
Pathol DOI 10.1007/s12024-012-9347-9, 2012 (levelV)

FigureThoracic aortic aneurysm rupture

The crescent shaped high density which is surrounded by an iso-density present at
the left pleural space. The high density is estimated to be coagulated blood. The
mediastinum right side shift is also marked. Using MPR imaging, it is helpful toassume the lesion distribution. Thoracic aortic dilatation is present at the aorticarch with irregular calcification, but the exact rupture point is difficult todetermine.

FigureAbdominal aortic aneurysm rupture

An abdominal aortic aneurysm was reported in the past history of this person.
Because of the general health condition, this lesion did not admit of surgicalintervention and was kept under observation without hospitalization. The patient
was discovered on the dressing room floor. This postmortem CT scan presents theabdominal aortic aneurysm with a retroperitoneal high-density, and it is expected
as showing abdominal aortic rupture and retroperitoneal hemorrhage.

CQ15 What are useful findings of postmortem imaging in the diagnosis ofdrowning? Is postmortem imaging useful to differentiate pulmonary edema causedby drowning from the edema caused by acute cardiac failure?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
Water in the paranasal sinuses and the mastoid air cells, fluid collection andhigh-attenuation sediment in the airways, ground-glass opacity within the lungs,
pleural effusion, and gastric extension are considered valuable, frequent findings
suggesting drowning.
However, these findings are not specific to drowning. Therefore, a differential
diagnosis is difficult.
Explanation
Drowning
Drowning is the result of a hampering of respiration by obstruction of airways by afluid medium. Therefore, it is classified as suffocation.
Though the mechanism of drowning in fresh or seawater is different, factors such aschanges in circulation volume and hemolysis caused by drowning, fatal arrhythmia
caused by electrolyte abnormalities, and circulatory insufficiency caused by cardiac
pump failure are considered to contribute to the cause of death.
The crucial point in investigations of bodies recovered out of water is whether thevictim died due to ‘true’ drowning or by immersion death. However, autopsy
techniques also find this differentiation difficult1).
A white plume of froth found in the airways from the mouth and nostrils to thebronchi, lung emphysema and edema aquosum, aqueous pulmonary edema in the
split surface, fluid collection in the thoracic cavity caused by postmortem leakage ofaspirated fluid, and the detection of diatoms in the organs are considered valuable
indications of drowning at autopsies.
However, findings of washerwoman’s hand and horripilation, damage caused byaquatic animal phagocytosis and underwater movement, and cooling of the bodymay be caused after death. Therefore, such findings are simply indications that acorpse has been immersed in water.

Sings of drowning in Postmortem CT scans
A number of reports of Postmortem CT scan findings in drowning have reported
that2)3) water and high-attenuation sediment in the paranasal sinuses and airways,
mastoid air cell fluids, plumes of froth in the airways, ground-glass opacity within
the lungs, pleural effusions, thickening of interlobular septa, and gastric extensions
may be considered characteristic to drowning.2)3).
Levy, et al.2 ） concluded that frothy airway fluid and high-attenuation airway
sediment strongly suggest drowning because such findings have only been made incases of drowning.
Other reports 4) found that postmortem CT scans could not detect the white frothy
airway fluid which is detected by autopsies, and this finding cannot be considereddefinite.
Further, as high-attenuation airway sediment is a sign of sand grains in theaspirated fluid, its specificity is high but the sensitivity depends on the nature of
the aspirated fluid.
Since airways, including the paranasal sinuses, are cavities open to the outside, thepossibility of passive intrusion of fluid into the airways is possible and fluid
identified here need not be a positive finding to indicate drowning.
As a key point to differentiate pulmonary edema caused by drowning and not bycirculatory failure, Christe, et al. 3) report that ground-glass opacity within thelungs in cases of drowning shows a characteristic ‘mosaic pattern’ and this would be
an important point to differentiate if pulmonary edema is caused by drowning
rather than caused by circulatory failure.
There are also reports that have found the proximity of the bilateral lungs in theanterior mediastinum to be a specific sign of the bulging lungs found in drowning.
Since all of these determinations are based on overall frequencies and trends
without sufficient statistical analysis, these findings can only be considered
supportive in a final determination of drowning.
It is important not to think that the cause of death is drowning in cases where allthese characteristic findings are absent.

Reference
1. Piette MHA, et al: Drowning: Still a difficult autopsy diagnosis. Forensic Science
International 63: 1–9, 2006 （levelⅣ）
2. Levy AD, et al: Virtual autopsy: two- and three-dimensional multidetector CT
findings in drowning with autopsy comparison. Radiology 243: 862-8, 2007 （levelⅣ）
3. Christe A, et al: Drowning--post-mortem imaging findings by computed
tomography. Eur Radiol 18: 283-90, 2008 （levelⅣ）
4.

Watanabe S, et al: Postmortem CT and autopsy findings. 5 drowning case,Houigaku-no-Jissaitokenkyuu. 52; 25-33, 2009 （levelⅣ） (Japanese)FigureDrowning

a. Maxillary sinus fluid collection
b. Fluid collected at the trachea and bronchus
c. A fluid-fluid level (horizontal sign) is present in the right atrium (arrowhead),and so the blood can be expected to be liquid. Bilateral pleural space fluid
collection is demonstrated.

d. On the lung window setting, there is diffuse lung opacity, the so-called diffuse
lung pattern. The hypostasis is not predominant in drowning cases.
e. At the autopsy, the lung parenchyma is expanded with edematous changes (theso-called emphysema aquosum). The anterior junction line is close.
f.

The lung parenchyma presents rich aeration and a rib compression mark at thelateral surface.

CQ16 What are useful findings to determine hypothermia in postmortem imaging?

Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
In postmortem CT scans, the preserved air densities in the lungs, clot formation in
the cardiovascular system (cast-like high-density structures), or high-volumes ofurine in the bladder, are suggestive of hypothermia.
Explanation
BackgroundHypothermia is a fatal state directly causing death from fatal decreases in vitality
due to low body temperature caused by exposure to cold. At autopsies, it is known
that findings of hypothermia deaths may include gastric black spots of hemorrhages(Wischnewski spots), color differences between the right and left heart blood,
collapsed lungs, and urine collected in the bladder. However, hypothermic deaths
are difficult to diagnose solely by these findings. Consideration for why a victim was
exposed to and did not escape from a cold environment must be considered. The
above autopsy findings only suggest “direct causes of death” but not “original causesof death” or the “manner of death”. For example, murder may be the original cause
if someone on purpose has left the victim in the cold environment. If the victim
developed hypothermia as a result of immobilization from diabetic coma, hepatic
encephalopathy or cerebral infarctions, this could be death by these diseases.
Recently, reports published by Japanese researchers have investigated postmortem
computed tomography (PMCT) findings of hypothermia, and these will be discussed
in this section. However, there are further problems to be discussed before
determining hypothermic death only supported by PMCT findings. At this point, it
is recommended that readers must show caution when determining hypothermic
deaths as mentioned above and determinations have to be made carefully, in acase-by-case manner. If there are still unknown aspects that may have been
overlooked after this approach is invoked, the readers of the PMCT scans must
persuade the law enforcement officers to do further investigation and autopsy.
Preservation of air-densities in the lungs
Increased densities in particular depending on the part of the lungs, so-called“hypostasis”, are usually found in postmortem imaging1). In hypothermic deathcases, these hypostatic changes are not clearly seen, and air densities may bepreserved in the lungs like antemortem images.
Hyodoh et al. reported that the proportion of lung volume with air densities (-700 to-1000HU) to lung total volume is significantly higher in hypothermic deaths than in
non-hypothermic deaths, from results of a comparison of 13 cases and 118 controls2).
Kawasumi et al. reported that increased lung densities occurred significantly lessfrequently in a hypothermic death group (n=24) than in a non-hypothermic deathgroup (n=53) 3). Michiue et al., in an examination of 135 cases including 8
hypothermic deaths, classified some groups of PMCT images using somemeasurements such as the mean CT scan values in axial images of the lungs andshowed that hypothermic deaths belong to the group of the least increased
densities4). In this report, deaths due to malnutrition or obstructive pulmonary
diseases are also categorized into this pattern, suggesting a potential differential
diagnosis.
Intravascular clot
In PMCT, high-density cast-like structures can sometimes be seen in the heart andaorta5). Kawasumi et al. reported that such findings are significantly more frequent
in hypothermic deaths than in non-hypothermic deaths3).
Volume of liquid in the bladder
In autopsies, it is known that the volume contained in the bladder increases inhypothermic death cases and assumed this to be caused by a longer time course
prior to death. Kawasumi et al. reported that if the cutoff value was set at 67.1 ml
for bladder volume, the volume is significantly higher in hypothermic deaths than
non-hypothermic deaths3).
In cases with all the 3 findings
Kawasumi et al. reported that if the 3 findings above are all in PMCT, thesensitivity and specificity for the diagnosis of hypothermia becomes 29.2% and100% respectively3). The results show high diagnostic values with very highspecificity, but there are still some limitations on the validity, including
uncertainties in the definition of hypothermic deaths in this report. Besides, even if
these findings appear on PMCT scans, the “original cause of death” and “manner ofdeath” are still unclear and requiring a case-by-case, comprehensive diagnosis asstated above.
*If these three findings are all identified in PMCT scans to determine the causes ofdeath requires establishment of the origin of the hypothermia. As long as the origin
is unclear, it is recommended to persuade law enforcement officers to conduct
further investigation and autopsies.
Search formula・secondary references
The authors performed a search of Pubmed for the recent 10 years using combined
keywords as follows; “postmortem CT” or “postmortem imaging” or “forensic
radiology” or “virtual autopsy” or “virtopsy”, hypothermia, and cause of death.

Reference
1. Shiotani S, et al: Non-traumatic postmortem computed tomographic (PMCT)
findings of the lung. Forensic Sci Int 139:39-48, 2004 （levelⅣ）
2. Hyodoh H, et al: Postmortem computed tomography lung findings in fatal of
hypothermia. Forensic Sci Int 231:190-4, 2013 （levelⅣ）
3. Kawasumi Y, et al: Hypothermic death: possibility of diagnosis by post-mortem
computed tomography. Eur J Radiol 82:361-5, 2013 （levelⅣ）
4. Michiue T, et al: Quantitative analysis of pulmonary pathophysiology using
postmortem computed tomography with regard to the cause of death. Forensic Sci
Int 220:232-8, 2012 （levelⅣ）
5. O'Donnell C, et al： Post-mortem radiology--a new sub-speciality? Clin Radiol
63:1189-94, 2008 （levelⅥ）

FigureHypothermic deatha. Postmortem lung image presenting high aeration (low hypostasis), similar tothe lungs of a living person.
b. At the autopsy, the lung weight was about 112 g for the left lung and about
112 g for the right lung. Both lungs show little edematous change and bright
red color, macroscopically.
c. The fluid-fluid level (horizontal line) is presented at the right atrium, andthe left ventricle, so the blood is expected to be liquid. The typical blood format hypothermic death cadavers report liquidity of the blood, and this casealso presents blood in the liquid form.
d. The color difference between venous and arterial blood is also a typicalfinding in hypothermic deaths (cadavers).
e. The stomach contains iso-density fluid.
f.

In the macroscopic investigation, the mucosal membrane shows spots
including bleeding spots (so called Wischnewski spots), but it is difficult to
detect these on the postmortem CT scans.

g. The urinary blood volume tends to increase in hypothermic deaths.
There is no sign of any cause of death in this case, and hypothermic death may
be expected as the cause of death here.

CQ17 What findings are useful in estimating starvation while alive on postmortem
CT scans?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
It is reported that emphysematous changes or hyperlucency of the lung may be
identified as establishing starvation on postmortem CT scans. However, suchfindings are not specific to starvation. One study for patients with anorexia nervosa
who are considered to be similar to the persons showing a state of starvation
reported that there are findings of lung emphysematous changes, dilatation of theventricle and sulcus, decreased orbital fat, and enophthalmos. It is known thatforensic findings of death from starvation are the following: decreased subcutaneousfat, muscle atrophy, enophthalmos, or sunken intercostal space (also in the
hypochondriac part or iliac part) as external findings and effusion into body cavities(pleural effusion, ascites, pericardial effusion), decreased visceral fat, collapse of thedigestive tract, or enlargement of the gallbladder as internal findings. Thesefindings are possibly helpful in interpreting postmortem images. Research studies
of postmortem images of death from starvation are still too few and there is no solid
evidence to decide starvation based on such images. Reference criteria for adiagnosis of death from starvation by postmortem images have not been
established.
Explanation
definition of the starvation
Starvation is considered to be the state of a stoppage or lack of nutrient intake
which is needed for the maintenance of life. Death from starvation is the state ofbeing mortal resulting from exhaustion of internal energy sources. Decreased
subcutaneous fat, muscle atrophy, or loss of weight of organs other than the brain isobserved with severe emaciation. Edematous changes by hypoproteinemia, pleural
effusion, ascites, pericardial effusion, and others can occur since protein is used forthe energy source.
CT findings of starvation
Michaud et al. evaluated the relationship between cause of death and lung findingson postmortem CT scans using the CT value of lung parenchyma. They reported

that diffuse emphysematous changes and decreased vascularity of the lungs areobserved in the case of death from starvation, and that the mean and mode CT
value are -760 and -560 HU, respectively, reflecting the hyperlucency of the lungs (1).
However, these results are not sufficiently specific or sufficient to consider
postmortem changes, and there is still room for further elucidation. To date, there
are few studies about starvation and its signs on postmortem images.
External and internal findings of starvation
One study of death from hunger strikes or starvation reported that the following
external findings were identified: decreased subcutaneous fat, muscle atrophy,
enophthalmos (decreased orbital fat), sunken cheeks (also supraclavicular fossae,
intercostal spaces, hypochondriac, or iliac parts), and decubitus ulcers on sacral
areas and heels. In addition, pleural effusion, ascites, pericardial effusions,decreased visceral fat (also more omentum, mesenteric, pericaridial fat, and more),lack of digestive tract contents, enlargement of the gallbladder, or brain swellingare reported to be observed as internal findings (2,3). These findings may help todetermine starvation because forensic findings which are specific to starvation are
also found on postmortem images.
CT/MR findings of starvation while alive
Coxson et al. reported that long-time malnutrition led to emphysematous changes ofthe lungs on CT scans in patients with anorexia nervosa (6). This is related to aprevious study by Michiue et al. which reported hyperlucency of the lungs in casesof death from starvation.
Another study of head CT scans of patients with anorexia nervosa reported thatdilatation of the ventricles and sulcus, increased density of orbital or subcutaneousfat, decreased orbital fat, and enophthalmos (5). It is also reported dilatation of theinferior horn of the lateral ventricle and sulcus, disappearance of fat signal
intensity of the skull bone marrow, cranial subcutaneous tissue, and orbit on head
MRI scans (6,7).
Discussion
Emphysematous changes of the lungs on postmortem CT scans may suggest a stateof starvation, it is insufficient to determine death from starvation by only thisfinding and other information such as external findings is needed for a final
evaluation.

Several studies reported significant decreases in fat, enophthalmos, and otherexternal findings for death from starvation before the autopsy. It is reported that
there are findings reflecting emaciation in patients with anorexia nervosa on
CT/MRI scans and similar findings may possibly be identified on postmortem
CT/MRI scans. Brain swelling as an internal finding and brain atrophy inpremortem CT/MR scan findings are reported to have been observed for the state of
starvation. Conflicting findings including brain swelling which is observed in
autopsies is thought to be caused by “normal” postmortem changes and notnecessarily due to a state of starvation.
Research methodology and supplementary materials
The following terms were used to search PubMed: postmortem, forensic, CT,
computed

tomography,

MRI,

magnetic

resonance

imaging,

malnutrition,

undernourishment, undernourished, poor nutrition, undernutrition, emaciation,
starve, starving, starvation, hunger, death.
References
1. Michiue T et al: Quantitative analysis of pulmonary pathophysiology using
postmortem computed tomography with regard to the cause of death. Forensic Sci
Int 220:232-238, 2012 (level Ⅳ)
2. Altun G et al: Deaths due to hunger strike: post-mortem findings. Forensic Sci Int
146:35–38, 2004 (level Ⅴ)
3. Solarino B et al: Child starvation and neglect: A report of two fatal cases. J
Forensic Leg Med 19:171-174, 2012 (level Ⅴ)
4. Coxson HO et al: Early emphysema in patients with anorexia nervosa. Am J
Respir Crit Care Med 170:748-752, 2004 (level Ⅳ)
5. Demaerel P et al: Orbital fat edema in anorexia nervosa: A reversible finding.
AJNR 17:1782-1784, 1996 (level Ⅴ)
6. Drevelengas A et al: Reversible brain atrophy and subcortical high signal on MRI
in a patient with anorexia nervosa. Neuroradiology 43:838-840, 2001 (level Ⅴ)
7. Okamoto K et al: Change in signal intensity on MRI of fat in the head ofmarkedly emaciated patients. Neuroradiology 43:134-138, 2001 (level Ⅳ)

FigureAn autopsy of a death from starvation

This female had a medical history of anorexia nervosa and living alone, and was
discovered dead in her room. Height: 154 cm, Weight: 32 kg (BMI 13.85). Atrophic
changes to the brain were not observed and there is no apparent sulcus (A). The
heart appears small on the chest CT scan (weight of the heart: 150 g) (B). The
lucency of the lungs is significantly high and there is no hypostasis in the lungs(weight of left and right lungs: 150 g and 158 g, (C). Abdominal organs and internal
genitalia are atrophic (weight of the liver, spleen, pancreas, and internal genitalia(uterus and ovaries): 700 g, 36 g, 19 g and 66 g, respectively), and there is no
gastrointestinal matter (D). Muscles are atrophic and subcutaneous fat issignificantly poor. The autopsy showed no fatal lesions or injuries other than thefindings of severe emaciation and atrophic organs.

CQ18 Is it possible to diagnose malignant neoplasms on postmortem CT scans?
Grades of recommendation: C1
Many investigators have reported that malignant neoplasms are presented as solid
tumors on postmortem CT scans and that this was confirmed by autopsies. However,
the origin or pathology of the tumors was difficult to determine. The usefulness of apostmortem biopsy was reported to be able to investigate the pathology. Similarfindings with other diseases may be misdiagnosed as malignant neoplasms. Some
infiltrated tumors cannot be identified on postmortem CT scans. It is not possible toidentify all malignant neoplasms on postmortem CT scans.
Explanation
Background
Malignant neoplasms have maintained the position as most common among causesof death in Japan since 1981. They account for 28.5% of the number of deaths in2011.
Neoplasms which can be identified on postmortem CT scans
Pulmonary tumors, tracheal tumors, pleural tumors, pharyngeal tumors, intestinal
tumors, hepatic tumors, brain tumors, and adrenal tumors have been reported tohave been identified on postmortem CT scans and have been confirmed by autopsies.
Robert et al. reported that it was not possible to distinguish primary lung cancers
from metastatic tumors or liver tumors from abscesses, which were identified on
postmortem CT scans. A postmortem biopsy is useful for a histopathologicaldiagnosis, which is necessary to make a definitive diagnosis. Robert et al. also
reported that pancreatic cancers and gallbladder cancers have been misdiagnosed
as duodenal cancers. It appears to be difficult to diagnose the tumor location
correctly.
Neoplasms which cannot be detected on postmortem CT scans
Metastatic pulmonary tumors, colon cancers, bronchial cancers, gastric cancers, andpulmonary cancers have not been reported as detected on postmortem CT scans.
Pulmonary cancers may be difficult to detect when they are not solitary, overlapping
other structures, or small.
It is reported that some malignant neoplasms, including infiltrated hepaticmetastases (breast cancers, malignant lymphomas, lung cancers, prostatic cancers,
renal cancers, melanomas, and neuroblastomas), pancreatic cancers, andpulmonary artery embolisms due to tumors were not detected clinically on CT scans
and were only diagnosed by autopsies after death. Such tumors would not be
possible to detect on postmortem CT scans.
Additional remarks
If malignant neoplasms were diagnosed before death, only some tumors can bedetected on postmortem CT scans. It is necessary to show care in diagnosing tumor
recurrences because some diseases show findings similar to tumor recurrences.
O’Donnell et al. reported liver metastases which were clearly demonstrated on
postmortem contrast CT scans. It is possible that postmortem contrast CT scan
examination is useful to detect tumors.

Reference
1. Homepage of Health, Labour and Welfare Ministry. 2013 (2014/2/14)
http://www.mhlw.go.jp/toukei/saikin/hw/jinkou/geppo/nengai12/dl/gaikyou24.pdf
2. Ikeda G, et al: Postmortem computed tomography and magnetic resonanceimaging in a case of terminal-stage small cell lung cancer: an experience of autopsy
imaging in tumor-related death. Radiat Med 25(2):84-7, 2007 (levelV）
3. Bolliger SA, et al: Postmortem imaging-guided biopsy as an adjuvant tominimally invasive autopsy with CT and postmortem angiography: a feasibility
study. AJR Am J Roentgenol 195(5):1051-6, 2010 (levelIV）
4. Poulsen K, et al: Computed tomography as routine in connection withmedico-legal autopsies. Forensic Sci Int 171(2-3):190-7, 2007 (levelV）
5. Roberts IS, et al: Post-mortem imaging as an alternative to autopsy in the
diagnosis of adult deaths: a validation study. Lancet 379:136-42, 2012 (levelIV）
6. Li HJ et al: Diagnostic imaging, preautopsy imaging and autopsy findings of 8
AIDS cases. Chin Med J (Engl) 122(18):2142-8,2009 (levelIV）
7. O'Donnell C, et al: Demonstration of liver metastases on postmortem whole bodyCT angiography following inadvertent systemic venous infusion of the contrast
medium. Int J Legal Med 126(2):311-4, 2012 (levelV）
8. Weustink AC, et al: Minimally invasive autopsy: an alternative to conventional
autopsy? Radiology 250(3):897-904, 2009 (levelIV）
9. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22(1):152-60, 2012 (levelIV）
10. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14(5):239-45, 2012 (levelIV）
11. Yamazaki K, et al: Comparison between computed tomography (CT) and autopsy
findings in cases of abdominal injury and disease. Forensic Sci Int 162(1-3):163-6,
2006 (levelIV）
12. Hanamornroongruang S, et al: Acute liver failure associated with diffuse liver
infiltration by metastatic breast carcinoma: A case report. Oncol Lett 5(4):1250-2,
2013 (levelV）
13. Simone C, et al: Rapid liver enlargement and hepatic failure secondary toradiographic occult tumor invasion: two case reports and review of the literature.
Journal of medical case reports 6(1):402, 2012 (levelV）
14. Allison KH, et al: Radiographically occult, diffuse intrasinusoidal hepaticmetastases from primary breast carcinomas: a clinicopathologic study of 3 autopsy
cases. Arch Pathol Lab Med 128(12):1418-23, 2004 (levelV）
15. Rowbotham D, et al: Acute liver failure secondary to hepatic infiltration: a single
centre experience of 18 cases. Gut 42(4):576-80, 1998 (levelV）
16. Kitanaka A, et al: Intravascular large B-cell lymphoma with FDG accumulationin the lung lacking CT / (67) gallium scintigraphy abnormality. Hematologicaloncology 27(1):46-9, 2009 (levelV）
17. Hishinuma S, et al: Patterns of recurrence after curative resection of pancreaticcancer, based on autopsy findings. J Gastrointest Surg 10(4):511-8, 2006 (levelIV）
18. Lammi M, et al: Pulmonary tumor embolism. Lung 188(5):441-3, 2010 (levelV）
19. Wichmann D, et al: Virtual autopsy as an alternative to traditional medical
autopsy in the intensive care unit: a prospective cohort study. Ann Intern Med
156(2):123-30, 2012 (levelIV）

FigureEsophageal carcinomaa.b.

This postmortem CT scan presents a soft tissue density mass at the thoracic

esophagus.
c.d. High density collection is clearly visible in the stomach and duodenum, andintestinal bleeding may be expected as the cause of death. The liver parenchyma

presents deformities and has a lower density than the spleen, so that liver cirrhosis
with fatty changes may be expected.
e.

At the autopsy, the esophageal carcinoma with coagulation was detected.

Partial tumor necrosis is also detected.
Gastrointestinal bleeding hypotension is expected as the cause of death.

CQ19 Can postmortem imaging diagnose the direct cause of death due to malignant
neoplasms?
Grade of Recommendation: C2
Reported findings of lethal organic malignant neoplasms confirmed to be the directcause of death by autopsy include respiratory failure due to severe malignant
pleural effusion, liver failure due to diffuse liver metastases, heart failure due tomyocardial metastasis, pulmonary artery tumor embolisms, and severe ascites due
to peritoneal dissemination. Among these findings, severe pleural effusion andascites can be detected with postmortem CT scans, but diffuse liver metastases,
myocardial metastasis, and pulmonary artery tumor embolisms are difficult to
detect.
Explanation
Malignant neoplasms diagnosed as the direct cause of death with postmortem CT
scans
Some studies have reported that malignant neoplasms can be detected with
postmortem CT scans 1-9); however, no studies have focused on malignant neoplasms
as a direct cause of death. One case report described a patient where the cause ofdeath was diagnosed as asphyxiation due to endobronchial metastasis from a renal
carcinoma with postmortem CT scans; however, the diagnosis was not confirmed bytraditional autopsy 10).
Malignant neoplasms diagnosed as the direct cause of death with clinical CT scans
In clinical settings, reported cases of lethal organic malignant neoplasms as the
direct causes of death include: respiratory failure due to severe malignant pleural
effusion caused by pleural dissemination of breast cancer, lung cancer, ovariancancer, and mesotheliomas 11); liver failure due to diffuse liver metastases 12-15);
heart failure due to metastasis into myocardia and cardiac outflow tracts 16) 17);
pulmonary artery tumor embolisms 18); and severe ascites due to peritoneal
dissemination of ovarian cancer 19). As somatic cavities are easy to assess with CT
scans, severe pleural effusion and ascites can be diagnosed with postmortem CT
scans 8). Diffuse liver metastases 12) 13) 15), myocardial metastasis, and tumor
embolisms 16-18) are difficult to diagnose even with clinical (antemortem) CT scansand often cannot be detected with postmortem CT scans.

Research methodology and supplementary materials
The following terms were searched for on PubMed with parameters defined to bewithin the past 10 years: postmortem CT, malignancy, autopsy, causes of death.
Referenced documents in the resulting articles and other useful papers have also
been cited.
References
1. Ikeda G et al: Postmortem computed tomography and magnetic resonanceimaging in a case of terminal-stage small cell lung cancer: an experience of autopsy
imaging in tumor-related death. Radiat Med 25:84-87, 2007 (level5)
2. Bolliger SA et al: Postmortem imaging-guided biopsy as an adjuvant to minimallyinvasive autopsy with CT and postmortem angiography: a feasibility study. AJR
195:1051-1056, 2010 (level 4)
3. Poulsen K, Simonsen J: Computed tomography as routine in connection withmedico-legal autopsies. Forensic Sci lnt 171:190-197, 2007 (level 4)
4. Roberts IS et al: Post-mortem imaging as an alternative to autopsy in the
diagnosis of adult deaths: a validation study. Lancet 379:136-142, 2012 (level 4)
5. Li HJ et al: Diagnostic imaging, preautopsy imaging and autopsy findings of 8
AIDS cases. Chin Med J (Engl) 122:2142-2148, 2009 (level 4)
6. O'Donnell C et al: Demonstration of liver metastases on postmortem whole bodyCT angiography following inadvertent systemic venous infusion of the contrast
medium Int J Legal Med 126:311-314, 2012 (level 4)
7. Weustink AC et al: Minimally invasive autopsy: an alternative to conventional
autopsy? Radiology 250:897-904, 2009 (level 4)
8. Takahashi N et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22:152-160, 2012 (level 4)
9. Kasahara S et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: a review of 339 forensic cases. Leg Med (Tokyo)
14:239-245, 2012 (level 4)
10. Takahashi N et al: Multiple lung tumors as the cause of death in a patient with
subarachnoid hemorrhage: postmortem computed tomography study. Jpn J Radiol

27:316-319, 2009 (level 4)
11. Davidson B: Malignant effusions: from diagnosis to biology. Diag Cytopathol
31:246-254, 2004 (level 6)
12. Hanamornroongruang S, Sangchay N: Acute liver failure associated with diffuse
liver infiltration by metastatic breast carcinoma: a case report. Oncol Lett
5:1250-1522, 2013 (level 5)
13. Simone C et al: Rapid liver enlargement and hepatic failure secondary toradiographic occult tumor invasion: two case reports and review of the literature. J
Med Case Rep 6:402, 2012 (level 5)
14. Rowbotham D et al: Acute liver failure secondary to hepatic infiltration: a single
centre experience of 18 cases. Gut 42:576-580, 1998 (level 5)
15. Allison KH et al: Radiographically occult, diffuse intrasinusoidal hepatic
metastases from primary breast carcinomas: a clinicopathologic study of 3 autopsy
cases. Arch Pathol Lab Med 128:1418-1423, 2004 (level 5)
16. Sawada Y et al: Remarkable tumor lysis in a hepatocellular carcinoma patient
immediately following glypican-3-derived peptide vaccination: An autopsy case.
Hum Vaccin Immunother 9:1228-1233, 2013 (level 5)
17. Murakami T et al: Cardiac metastasis of renal pelvic cancer. Int J Urol
14:240-241, 2007 (level 5)
18. Lammi M et al: Pulmonary tumor embolism. Lung 188:441-443, 2010 (level 5)
19. Yamasaki M et al: An autopsy case died of untreated ovarian carcinoma. Acta
Criminologiae et Medicinae Legalis Japonica 66: 209-216, 2000 (level 5)

CQ20 What radiological findings are useful in the diagnosis of pneumonia with
postmortem CT scans?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
A previous study of postmortem CT scanning reported that segmental
consolidations and multiple fused patchy consolidations were identified in caseswith pneumonia. However, these findings are not specific to pneumonia. Similarfindings have been reported with postmortem CT scans from patients with
nonpathologicalpostmortem

changes(lungcadavericlividity),

pulmonarycongestion, or pulmonary edema.
The diagnosis of pneumonia with postmortem imaging has not yet been fully
investigated and there is insufficient evidence to draw final conclusions. The
diagnostic criteria for pneumonia with postmortem CT scans have not yet been
established.
Explanation
A previous descriptive study reported that the abovementioned findings with
postmortem CT scans were observed in cases with pneumonia 1). These findings
would suggest the possibility of pneumonia. However, no radiologic–pathologic
correlation was investigated in the study. Further, the study showed several
limitations as follows: cases with severely damaged bodies (cadavers), chest trauma,
hemothorax and pneumothorax, severe pleural effusion, and putrefaction gas were
excluded; the presence or absence of laterality in lung findings were not considered;
elapsed time since death was not assessed (the influence of lung cadaveric lividity
as a non-pathological postmortem change2)

was not considered). Therefore,

pneumonia as a cause of death should be diagnosed with caution based on thesefindings (Figure 1).
A study on the diagnosis of causes of death in adults reported a 32% discrepancy ofcases between the diagnoses with postmortem CT scans, those interpreted byradiologists without a specialty in postmortem imaging, and those made by
autopsies3). With imaging, 32% of bronchopneumonia cases were overlooked in thesame study. The majority of lung findings with postmortem CT scans are
non-specific and not helpful for establishing the cause of death 4). Elapsed time sincedeath must be considered as a necessary parameter.

Research methodology and supplementary materials
A search for the words (postmortem, pneumonia, and death) was conducted on
PubMed.
References
1. Michiue T et al: Quantitative analysis of pulmonary pathophysiology using
postmortem computed tomography with regard to the cause of death. Forensic Sci
Int 220:232-238, 2012 (level 5)
2. Shiotani S et al: Postmortem pulmonary edema: a comparison between
immediate and delayed postmortem computed tomography Leg Med (Tokyo)
13:151-155, 2011 (level 5)
3. Roberts IS et al: Post-mortem imaging as an alternative to autopsy in the
diagnosis of adult deaths: a validation study. Lancet 379:136-142, 2012 (level 4)
4. Shiotani S et al: Non-traumatic postmortem computed tomographic (PMCT)
findings of the lung. Forensic Sci Int 139:39-48, 2004 (level 4)
5. Hasegawa I et al: Postmortem imaging: Transition of postmortem findings inserial postmortem scans. Jpn J Forensic Pathol 26:97-102, 2010 (level 5)

FigureAn autopsy case of pneumonia.

Postmortem CT images show remarkable consolidations and the air bronchogram
mainly on the dorsal side of the bilateral lungs (A) and pleural effusion in the rightpleural cavity (B). In the autopsy, the left lung was found to be sclerotic and heavy(916g). Macroscopically, the left inferior lobe was solid with a blistered patchy
pattern on the surface (C); this was diagnosed as pneumonia. Histologically, withthe background of severe emphysema, highly aggregated intra alveolar leukocytes,
destroyed alveoli, and fibrin depositions were observed (D).

CQ21 Is postmortem imaging useful when determining death from asphyxia?
Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death
In determining death from asphyxia, there are some uses for postmortem imaging
to investigate deaths by obstruction of airways or neck compression from theoutside. Foreign objects or masses in the airways, hemorrhages in cervical soft
tissue, or fractures of the hyoid bone or thyroid cartilage may show up and thesefindings can be useful in determining deaths from asphyxia. Improvement of thediagnostic accuracy is expected by using multi-planar reconstructed images ifnecessary. It is thought that to clearly show findings on postmortem images which
are related to the causes of asphyxia will play a supportive role, but the findings
may sometimes be modified by resuscitation.
Explanation
Definitions for asphyxia
Unless otherwise noted, asphyxia in the field of forensic medicine is defined as astate mechanical disorder of the external respiration (the processes of the intake ofoxygen from the airway inlet to the alveoli and exchange of gases between thealveoli and the blood). Mechanical asphyxia is classified as follows (mainly 1-5):
1. obstruction of nostrils
2. obstruction of the upper airway lumen
3. neck compression from the outside (hanging, strangulation)
4. obstruction of the peripheral airways (drowning and others) (CQ15)
5. breathing disorders (chest or abdominal compression, pneumothorax, and others)
6. abnormalities of the inhaled air or oxygen deficiency (sewerage accidents andothers)Postmortem images of obstruction of the upper airways
It is reported that foreign objects or masses in the nasal cavity or trachea whichlead to asphyxia can be identified on postmortem CT/MRI scans (1-8). Foreign objects
in the pharynx or larynx by Iino et al. (1), in the larynx by Oesterhelweg et al. (2), andin the trachea by Aquila have been identified on postmortem CT scans (3). Thali et al.
reported that foreign objects in the airways were clearly identified on postmortem
CT scans in a putrefied cadaver one year after interment, and the cause of deathwas overturned (4).
It is also reported that metastasis of the tracheal lumen (5) and hemoptysis due totuberculosis (6) are shown as possible causes of asphyxia except for the presence of
foreign objects. In other cases, postmortem CT scans showed that Ludwig angina
which is a fatal and severe infectious disease in the submandibular region causes
soft tissue swelling and upper airway obstruction (7).
The slice thickness of postmortem CT scans aiming to identify foreign objects
causing airway obstruction varies from 0.5 to 2mm (1,2,9). It is thought that at least a
5mm slice thickness is necessary to obtain images for reconstruction, such as
saggital, coronal, or 3D images. If possible, a 1-2mm slice thickness is better.
Enhanced CT/MRI scans can provide additional information although it is difficult
to evaluate something causing asphyxia or distinguish between foreign objects andlesions using the differences in CT values on unenhanced CT scans (2,4).
Postmortem CT/MRI scans make it possible to assess the state of the airway lumen
which is not possible by external examination and is of some usefulness whenscreening for matters such as foreign objects, masses, and similar which would leadto airway obstruction. An objective assessment for objects which may migrate
during an autopsy can also be possible. However, care must be shown in estimating
causes of death immediately after the occurrence when asphyxia is suspected to be a
result of airway obstruction due to foreign objects and similar. For example, there isa report of a mother who killed her baby by sticking her fingers into the mouth of
the baby and then left a number of leaves in the oral cavity (9). It should be taken
into account that there are some situations such as residue refluxes from thestomach and esophagus in the agonal stage, movement of an object in the airway
with posture changes of the cadaver, or intentional removal of objects after thedeath. There are some cases of suspicion of involvement in a crime or need toperform a toxicological examination and it is essential for the diagnosis of deathfrom asphyxia to make a general evaluation with information other than that frompostmortem images or other evidence.
Postmortem images of neck compression from the outside
In case of mechanical neck compression (classified into: hanging, ligature
strangulation, and manual strangulation), a major cause of death is blocking of theblood flow and oxygen supply to the brain due to the obstruction of cervical vessels.
Interpretation of images of asphyxia due to mechanical neck compression is mainly
an evaluation of the soft tissue, bone, and cartilage.

Based on postmortem images of hanging, Sohail et al. reported fractures of the
thyroid cartilage and laryngeal edema on CT scans (10), and Dubang et al. reported
adduction and closure of the vocal cords on MRI images (11). Aghayev et al. reported
that the hyoid bone and thyroid cartilage on CT scans and hemorrhage of theposterior cricoarytenoid muscle on MRI images were identified in the case ofligatures and manual strangulation (12). In addition, Kempter et al. reported thatfractures of the hyoid bone, cricoid, and thyroid cartilage were identified on CT
scans in 75% of cases of death from hanging and ligature strangulation. Airway
obstruction is not a necessary finding for death from neck compression andfractures of atlas or axis vertebra are not always established.
The MRI findings from cases of survivors from neck compression may be useful.
Christe et al. reported cervical subcutaneous and muscle hemorrhage in the case ofmanual strangulation (14) and Yen et al. reported hemorrhages of the subcutaneous
tissue, muscle, lymph node, and salivary glands, laryngeal edema, hematomas ofthe pharynx and larynx in the case of ligature strangulation (15).
The CT and MRI scans for evaluation of the neck region are useful but not essential.
Here, CT scans are superior to evaluate the bone and cartilage and multiple images
with multi-planar reconstruction makes diagnostic accuracy higher. However,finding tiny fractures on MRI images is not always easy. For evaluations of the soft
tissue structure, MRI images are recommended because the tissue contrast of MRI
is better (15) and CT scans may not be appropriate (13). Findings such as slighthemorrhages which are identified by MRI can be helpful for a diagnosis andcombining it with fat-suppression images will be necessary in the choice of scansequences (12,15).
When the postmortem image findings which suggest asphyxia due to neckcompression are poor, it is important to recognize that asphyxia may still be thecause of death. A multiplex diagnosis considering the situation of the death, withexternal and autopsy findings should be required.
Postmortem images of breathing disorders
Ito et al. reported a case of death from asphyxia by breathing disorder which was a
result of chest and abdominal compression by the victim being caught by a truck (16).
The postmortem CT showed a slight hemorrhage around the duodenum and aflattened aorta and inferior vena cava. The cause of death was decided from thepetechiae of the eyelids as an external finding and information from the scene.

Other notes
On postmortem imaging, it is difficult to assess petechiae of the face and eyes or
postmortem lividity and other signs which are forensic external findings of asphyxia.
When a cervical furrow caused by hanging is deep, it has been shown that thisfinding can be depicted in multi-planar reconstructed images using volume
rendering (VR) and similar (17). To date, there has not been studies about
postmortem imaging of internal findings such as congestion of various organs (lungs,
liver, kidney, brain, and others). It is unclear if postmortem imaging for nasal
obstructions, which is one of the signs of mechanical asphyxia, is useful. Further,chemical asphyxia by carbon monoxide poisoning (classified into poisoning as thecause of death) and mechanical asphyxia from oxygen deficiency cannot be
determined by postmortem imaging.
Remarks
Death from asphyxia is occasionally associated with a crime, and further
investigation or autopsy should be recommended to the investigating authority
while referring the situation of death, external findings, and other matters.
Research methodology and supplementary materials
The following terms were searched for on PubMed: postmortem, forensic, CT,
computed tomography, MRI, magnetic resonance imaging, asphyxia, asphyxiation,
suffocation, choking, smothering, and airway obstruction. The books entitled“autopsy imaging guide for interpretation” and “autopsy imaging cases series” arealso referred to.
References
1. Iino M et al. Postmortem computed tomography findings of upper airway
obstruction by food. J Forensic Sci. 55:1251-1258, 2010 (level Ⅴ)
2. Oesterhelweg L et al. Virtopsy: postmortem imaging of laryngeal foreign bodies.
Arch Pathol Lab Med. 133:806-810, 2009 (level Ⅴ)
3. Aquila I et al. Virtopsy versus autopsy in unusual case of asphyxia: case report.
Forensic Sci Int. 229:e1-5, 2013 (level Ⅴ)
4. Thali YA et al. Death by biscuit--exhumation, post-mortem CT, and revision of thecause of death one year after interment. Leg Med (Tokyo). 13:142-44, 2011 (level Ⅴ)
5. Takahashi N et al. Multiple lung tumors as the cause of death in a patient with
subarachnoid hemorrhage: postmortem computed tomography study. Jpn J Radiol.

27:316-319, 2009 (level Ⅴ)
6. Hamano J et al. Postmortem computed tomographic (PMCT) demonstration of
fatal hemoptysis by pulmonary tuberculosis--radiological-pathological correlation ina case of rupture of Rasmussen's aneurysm. Radiat Med. 22:120-122, 2004 (level Ⅴ)
7. Lee WI et al. Post-mortem CT findings in a case of necrotizing cellulitis of thefloor of the mouth (Ludwig angina). Forensic Sci Med Pathol. 10:109–113, 2014(level Ⅴ)
8. Iwase H et al. Evaluation of computed tomography as a screening test for deathinquest. J Forensic Sci. 55:1509-1515, 2010 (level Ⅴ)
9. Rutty GN et al. The use of post-mortem computed tomography in theinvestigation of intentional neonatal upper airway obstruction: an illustrated case.
Int J Legal Med. 124:641–645, 2010 (level Ⅴ)
10. Sohail S et al. Postmortem computed tomography for diagnosis of cause of deathin male prisoners. J Pak Med Assoc. 60:4-8, 2010 (level Ⅴ)
11. Duband S et al. Study of endolaryngeal structures by videolaryngoscopy after
hanging: A new approach to understanding the physiopathogenesis. Forensic Sci Int.
20:48-52, 2009 (level Ⅴ)
12. Aghayev E et al. Virtopsy hemorrhage of the posterior cricoarytenoid muscle byblunt force to the neck in postmortem multislice computed tomography andmagnetic resonance imaging. Am J Forensic Med Pathol.27: 25–29, 2006 (level Ⅴ)
13. Kempter M et al. Post-mortem imaging of laryngohyoid fractures in
strangulation incidents: First results. Leg Med (Tokyo). 11:267-271, 2009 (level Ⅴ)
14. Christe A et al. Can MRI of the neck compete with clinical findings in assessing
danger to life for survivors of manual strangulation? A statistical analysis. Legal
Medicine 12:228–232, 2010 (level Ⅳ)
15. Yen K et al. Clinical forensic radiology in strangulation victims: forensic
expertise based on magnetic resonance imaging (MRI) findings. Int J Legal Med.
121:115–123, 2007 (level Ⅴ)
16. Takahashi N, Shitani S, ed. Autopsy imaging case series, Vector Core, Tokyo,
pp102, 2012 (level Ⅴ)
17. Ohtono K, supervised. Autopsy imaging guide for interpretation, Bunko-do,
Tokyo, pp82-83, 2009 (level Ⅵ)

FigureFigure A case of asphyxia caused by airway obstruction due to “mochi” (a kind ofJapanese soft rice cake)A case of solitary death showed a hyperdense lump of material in the pharynx andlarynx. The horizontal plane is observed in the cardiac cavity on the chest CT scan(B) and this suggests flowing of blood and acute death. Although rigor mortis of thejaw was severe and examination of the oral cavity was impossible at thepostmortem examination, laryngeal obstruction by “mochi” was identified usingrhino-pharyngo-laryngoscopy.

Figure A case of death from hanging

Lateral difference in the position of the superior horn of the thyroid cartilage isobserved on the axial image (A). An anterior shift of the left superior horn of the
thyroid cartilage is clearly visible on the VR images (B, C).

CQ 22 Is it possible to use postmortem imaging to detect drugs in the stomach?
Grade of Recommendation: C1
There are reports of hyperdense stomach and duodenal contents being detected on
postmortem computed tomography (CT) scans. Postmortem CT scans are useful indetecting radiopaque medications, and toxicological analysis of blood and stomach
contents is recommended when there is hyperdense material in the stomach.
Explanation
Background
There are reports of hyperdense stomach and duodenal contents observed on
postmortem CT scans confirmed as being oral medications in subsequent autopsies(1-3). It has also been reported that hyperdense stomach contents were significantly

more frequent in a drug overdose group, suggesting a correlation with drug
intoxication (1).
Medications
Medications known to be radiopaque include bromine-containing medications suchas bromovaleryl urea (2,3); chloral hydrate, heavy metal and iron salts, phenothiazine,
and slow-release preparations (3). The necessary CT scan numbers of stomach
contents in drug intoxication depends on the density of the medication itself, but isalso affected by the amount of medication, the amount of food residue, time elapsed
after ingestion, and time elapsed after death (2). Drugs in the stomach andduodenum are often depicted as hyperdense precipitates on postmortem CT scans. A
case of organic mercury poisoning was reported as showing hyperdensity along theoral, esophageal, and gastric walls (4).
Significance detecting medications in the stomach
When drugs are retained in the stomach or duodenum, they are sometimes
hyperdense on postmortem CT scans. However, an absence of hyperdense masses inthe stomach and duodenum does not rule out drug intoxication (2). In addition, foodresidue in the stomach is often hyperdense, and it is often difficult to distinguish itfrom drugs in the stomach. The decision to perform a drug analysis should be madebased on all available information, including the circumstances of death.

Some radiopaque drugs cannot be detected in the Triage toxicology screening
examination, and when hyperdense stomach contents are detected on postmortem
CT scans, drug analysis of blood and gastric contents with the possibility of drug
intoxication in mind is recommended (1,3). However, quantification of drugs on CT
scans is difficult (3).
There has been a report of a case in which the circumstances of the death and thehyperdense stomach contents on the postmortem CT scans strongly suggested drug
intoxication. The subsequent blood test was positive for mercuric chloride poisoning.
Postmortem CT scans helped the forensic medicine staff avoid the risk of mercury
exposure during the autopsy and toxicological analysis (4).
Reference
1. Burke MP, et al: The use of postmortem computed tomography in the diagnosis ofintentional medication overdose. Forensic Sci Med Pathol 8:218-36, 2012 (level
IVb)
2. Aghayev E, et al: Radiopaque stomach contents in postmortem CT in suicidal oral
medication intoxication: report of three cases. J Forensic Leg Med 17:164-8, 2010(level V)
3. Sano R, et al: A case of fatal drug intoxication showing a high-density duodenal
content by postmortem computed tomography. Leg Med 13:39-40, 2011 (level V)
4. Iino M, et al: Post-mortem CT findings following intentional ingestion of mercuric
chloride. Leg Med(Tokyo) 11:136-8, 2009 (level V)

FigureDrug poisoning

High density material is present in the stomach (a). Bilateral diffuse ground glass
opacity is present in both lungs (b), and the urinary bladder contains an
extraordinarily large volume of urine (c). These are typical findings in drug
poisoning. In the autopsy investigation, a white material was found in the stomach,and a lethal dose concentration of drug was determined in the blood sample.

FigureStimulant poisoning and drowning

The cadaver was discovered at the bath tub. The injection needle mark was found at
the elbow and the drug screening test showed a stimulant positive reaction. On the
postmortem CT scan, high density material was present in the stomach, and the
cadaver is suspected to be a body packer. At the autopsy, un-chewed
putty-consistency rice (MOCHI) was found. Other food like noodles show highdensities on CT scans.

CQ23 Is postmortem imaging useful to detect and measure fluid in body cavities?
Grade of Recommendation: C1
Fluid in body cavities can be detected and measured on postmortem CT scans. In
comparison with autopsies, the location and relationship to other organs of the fluid
is accurately presented on postmortem CT scans. It is difficult to determine fluid
collection in some decomposed corpses however. It is also difficult to determine fluid
properties, whether serous, suppurative, or bloody, correctly.
Explanation
Background
Fluid collected in the sinonasal cavities, trachea, pleural cavities, pericardial
cavities, peritoneal cavities, and retroperitoneal cavities has been detected on
postmortem CT scans, and were confirmed by autopsies in many reports. It wasreported that small amounts of fluid collected in the pleural or pericardial cavities,
which were not noted by autopsies, were present on postmortem CT scans. Le
Blank-Louvry et al. reported that the detection rate of abdominal fluid collections
on postmortem CT scans is higher than that by autopsies. However, Poulsen et al.
reported that it is difficult to detect small volumes of abdominal fluid on
postmortem CT scans in decomposed corpses because of intestinal and peritoneal
gases.
Quantitative analysis of fluid collected in body cavities
Some studies reported that the amount of peritoneal blood or peritoneal fluid was
accurately measured on postmortem CT scans.
A comparison with autopsies
Because fluid moves during autopsies, it is difficult to determine its exact locationin body cavities. It is however possible to demonstrate the location and relationshipto other organs of fluid accurately on postmortem CT scans. Christoffersen reported
a case with compression to the mediastinum by a large volume of pleural effusion,
where the relationship between fluid and mediastinum was not detected by the
autopsy.
Blood collection in body cavities

Blood is usually shown as high opacities on postmortem CT scans. However the
opacity of blood in body cavities changes according to the conditions at the death orafter the death. As a result, it may be difficult to distinguish among fluid
characteristics, serous, suppurative, or blood. When characteristics of fluid in body
cavities are evaluated, it is important to record the conditions involved at death orafter death.
Reference
1. Kasahara S, et al: Diagnosable and non-diagnosable causes of death bypostmortem computed tomography: A review of 339 forensic cases. Leg Med (Tokyo)
14(5):239-45, 2012 (levelIVb）
2. Le Blanc-Louvry I, et al: Post-mortem computed tomography compared toforensic autopsy findings: a French experience. Eur Radiol 23(7):1829-35, 2013(levelIVb）
3. Wichmann D, et al: Virtual autopsy as an alternative to traditional medical
autopsy in the intensive care unit: a prospective cohort study. Ann Intern Med
156(2):123-30, 2012 (levelIVb）
4. Ruder TD, et al: Minimally invasive post-mortem CT-angiography in a caseinvolving a gunshot wound. Leg Med (Tokyo) 12(3):154-6, 2010 (levelV）
5. Takahashi N, et al: The effectiveness of postmortem multidetector computed
tomography in the detection of fatal findings related to cause of non-traumaticdeath in the emergency department. Eur Radiol 22(1):152-60, 2012 (levelIV）
6. Christoffersen S. CT verified cause of death in hepatic hydrothorax without
ascites. Forensic Sci Int 198(1-3):e11-3, 2010 (levelV）
7. Weustink AC, et al: Minimally invasive autopsy: an alternative to conventional
autopsy? Radiology 250(3):897-904, 2009 (levelIV）
8. Ebert LC, et al: CT based volume measurement and estimation in cases of
pericardial effusion. J Forensic Leg Med 19(3):126-31, 2012 (levelIV）
9. Cha JG, et al: Utility of Postmortem Autopsy via Whole-Body Imaging: Initial
Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings.
Korean J Radiol 11(4):395-406, 2010 (levelIV）
10. Christe A, et al: Abdominal trauma--sensitivity and specificity of postmortem
noncontrast imaging findings compared with autopsy findings. J Trauma
66(5):1302-07, 2009 (levelIV）
11. Miyamori D, et al: Temporal evolution in peritoneal hemorrhage as depicted bypostmortem CT. J Forensic Leg Med 20(5):548-50, 2013 (levelV）

12. Ampanozi G, et al: Post-mortem virtual estimation of free abdominal blood
volume. Eur J Radiol 81(9):2133-6, 2012 (levelIV）
13. Arai A, et al: Postmortem computed tomographic (PMCT) and postmortem
magnetic

resonance

imaging(PMMRI)

demonstration

of

fatal

massiveretroperitoneal hemorrhage caused by abdominal aortic aneurysm (AAA) rupture.
Radiat Med 24(2):147-9, 2006 (levelV）
14. Daly B, et al: Comparison of whole-body post mortem 3D CT and autopsy
evaluation in accidental blunt force traumatic death using the abbreviated injury
scale classification. Forensic Sci Int 225:20-6, 2013 (levelIV）
15. Poulsen K, et al: Computed tomography as routine in connection withmedico-legal autopsies. Forensic Sci Int 171(2-3):190-7, 2007 (levelV）

FigureDrowning

On the postmortem CT scan, the air-fluid level is present from the larynx to thetrachea (a), and bronchus (b). Bilateral pleural space fluid is also present on thechest CT scan. Using a tracheal fiberscope, white small bubbles were identified justbeside the vocal cord with fluid (c). At the autopsy, there were tracheal bubbles, but
the fluid leaked out during the procedure.

CQ 24 Is it possible to use postmortem imaging to detect and quantify gas incorpses?
Grade of Recommendation: C1
There are reports of detecting abnormal gas volumes in different parts of the bodyon postmortem computed tomography (CT) scans. Detection of internal gas on CT
scans is easier than at autopsies, and image reconstruction enables quantification.
Intravascular gas often develops during normal postmortem changes andresuscitation, but it may also be due to air embolism. The cause of intravascular gas
must be carefully identified by quantity and distribution, and the time elapsed after
death must also be noted. Gas in the abdominal cavity is an indirect finding
suggesting gastrointestinal perforation, but it is necessary to distinguish this gas
from that due to gastric perforation caused by postmortem autolysis. It is difficult toestimate the elapsed time after death by detection of internal gas alone.
Explanation
Background
There are reports of detecting abnormal gas in various parts of the body on
postmortem CT scans. Gas within organs such as the liver, kidneys, spleen, andpancreas (1,2); intravascular gas such as in the aorta, heart, and coronary artery (2-6);
andintracranial

emphysema,

mediastinal

emphysema,

pneumothorax,

pneumoperitoneum, and retroperitoneal emphysema (4,5,7) have been reported to beclearly depicted on postmortem CT scans.
Non-traumatic death
Intravascular gas in cases of non-traumatic deaths has two potential origins:decomposition and cardiopulmonary resuscitation (CPR) (1).
Decomposition begins immediately after death, and the generated gas is evenly
distributed in the abdominal organs. It is difficult to estimate time elapsed after
death from the distribution of gas on postmortem CT scans (1). But when
intravascular gas is determined in cases with images obtained more than one day
after death, decomposition should be considered a potential source of the gas, sincefindings of putrefaction appear on CT scans around 1-2 days after death (2). There isa report of a case in which intravascular gas on a CT scan made several hours

posthumously was diagnosed as a finding of decomposition (3), but details of the gas
were not analyzed.
There is also a report associating CPR with gas retention in the liver and kidneys (1)and such a finding can be helpful to distinguish the origin of the internal gas. In
addition, intracardiac and intravascular gas caused by CPR is thought to flow into
the brain vessels in a retrograde manner (3).
Intravasculargas,

subcutaneous

emphysema,

mediastinal

emphysema,

pneumothorax, pneumoperitoneum, and retroperitoneal hemorrhages caused byintentional gas infusion into the blood vessels have been reported to be clearly
depicted on postmortem CT scans (5,6). Image reconstruction is useful for recognizing
the distribution of the gas in the body and for quantifying the gas (6,7). However, it
has been reported that intra-arterial or intravenous infusion of gas from the limbs
can cause fatal air embolisms even in small quantities depending on the infusion
rate (8), and it may be difficult to decide the cause of death from postmortem CT
scans alone.
Free gas in the abdominal cavity on postmortem CT scans must be interpreted
carefully, because this gas can be due to gastric perforation caused by autolytic
rupture of the stomach after death (9,10). In the absence of findings indicating
decomposition and peritonitis on postmortem CT scans, abdominal free air may be
the result of gastric perforation due to postmortem autolysis.
Traumatic death
There are many reports of cases with arterial air embolisms after chest injuries,
and traumatic pulmonary alveolo-venous fistulas are considered to be the maincause (4). It has also been reported that head and neck injuries cause venous air
embolism (7). Arterial embolisms from venous gas, the so-called paradoxical
embolism, may be seen in patients with right-to-left shunt such as foramen ovale
and pulmonary arteriovenous fistula (5,6). These arterial air embolisms are
sometimes the cause of death, and the detection of intravascular gas is helpful infinding the probable cause of death. However, estimating the time elapsed after
death is difficult (1).
Reference
1. Ishida M, et al: Intravascular gas distribution in the upper abdomen of
non-traumatic in-hospital death cases on postmortem computed tomography. Leg
Med 13:174-9, 2011 (level V)

2. Jackowski C, et al: Intrahepatic gas at postmortem computed tomography:
forensic experience as a potential guide for in vivo trauma imaging. J Trauma
62:979-88, 2007 (level IVb)
3.

Shiotani

S,

et

al:

Nontraumatic

postmortem

computed

tomographic

demonstration of cerebral gas embolism following cardiopulmonary resuscitation.
Jpn J Radiol 28:1-7, 2010 (level IVb)
4. Brook OR, et al: Arterial air emboli on computed tomography (CT) autopsy. Injury
43:1556-61, 2012 (level V)
5. Laurent PE, et al: Post-mortem computed tomography in a case of suicide by air
embolism. Diagn Interv Imaging 94:460-2, 2013. (level V)
6. Makino Y, et al: Massive gas embolism revealed by two consecutive postmortem
computed-tomography examinations. Forensic Sci Int 231:e4–10, 2013 (level V)
7. Jackowski C, et al: Visualization and quantification of air embolism structure byprocessing postmortem MSCT data. J Forensic Sci 49:1339-42, 2004 (level V)
8. Inoue H et al: Cranial computed tomograms of arterial and venous cerebral air
embolism. Fukuoka Acta Med 96:326-30, 2006 （level V）
9. Dedouit F, et al: Lethal visceral traumatic injuries secondary to child abuse: acase of practical application of autopsy, radiological and microscopic studies.
Forensic Sci Int 206:e62-6, 2011 (level V)
10. O'Donnell CJ, et al: Postmortem CT findings of gastromalacia: a trap for theradiologist with forensic interest. Forensic Sci Med Pathol 6:293-7, 2010 (level V)

FigurePan peritonitis due to traumatic intestinal rupture

Intra-cardiac and intra-vascular gas is present, but there is no subcutaneous gas
formation (a). There is peritoneal free air and peritoneal fluid collected at the liverand splenic surface (b). Gastro-intestinal perforation is expected from these CT
image findings. At the autopsy, pan peritonitis due to traumatic intestinal rupture
was confirmed.

CQ25 Is postmortem imaging useful in determining rib fractures arising fromcardiopulmonary resuscitation?
Grade of Recommendation: C1
Postmortem imaging is useful in determining rib fractures due to cardiopulmonary
resuscitation (CPR) in case of nontraumatic cardiac arrest. Computed tomography(CT) is superior in this diagnosis because conventional chest X-ray images are
insufficient to determine such fractures. Localization and a qualitative diagnosis byreconstructed images from CT scans may enable distinguishing between fracturesassociated with CPR and fractures due to other causes.
Explanation
Chest compression is necessary during CPR after cardiac arrest. For adults
compression with a vertical depth of 5 cm in the supine position, is recommended.
Fractures in the ribs and sternum due to chest compression during CPR arefrequently reported in adults, although the incidence varies among studies.
A characteristic finding of rib fracture due to CPR is the “buckle fracture,” a type ofincomplete rib fracture that involves either the outer or the inner cortex alone. Over
95% of rib fractures associated with CPR are located in the anterior ribs, mostly
from the second to the seventh rib. If fractures are located in the posterior ribs, thepossibility of trauma other than CPR-associated trauma should be considered1). In
detecting buckle fractures, CT scans have been shown to be superior to autopsies
and conventional X-ray images for a diagnosis2), further, autopsies are superior toconventional X-ray images3). In patients where there is no resumption ofautonomous circulation after CPR, hemorrhagic complications are rarely due to
CPR-associated rib fractures3).
However, in cases in which chest compression was performed by AutoPulse, anautomated chest compression device, posterior rib fractures occur with a highfrequency4). In a study investigating 13 cadavers subjected to chest compression by
the LUCAS CPR, another automated chest compression device, the incidence andlocations of rib fractures were similar to those caused by manual CPR, andautopsies identified more fractures than CT scans5).
Research methodology and supplementary materials
The following terms were searched for on PubMed with parameters defined to bewithin the past 10 years: postmortem CT, CPR, rib fracture, and autopsy.
Referenced documents in the resulting articles and other useful papers have also
been cited, as well as studies of survivors from chest compression.
References
1. Yang KM et al. "Buckle" rib fracture: An artifact following cardio-pulmonary
resuscitation detected on postmortem CT. Leg Med (Tokyo) 13:233-9, 2011 (level 5)
2. Smekal D et al. Comparison of computed tomography and autopsy in detection of
injuries after unsuccessful cardiopulmonary resuscitation. Resuscitation 84:357-60,
2013 (level 4)
3. Lederer W et al. Frequency of rib and sternum fractures associated with
out-of-hospital cardiopulmonary resuscitation is underestimated by conventional
chest X-ray. Resuscitation 60:157-62, 2004 (level 5)
4. Pinto DC et al. Manual and automated cardiopulmonary resuscitation (CPR): A
comparison of associated injury patterns. J Forensic Sci 58(4):904-909, 2013 (level
4)
5. Oberladstaetter D et al. Autopsy is more sensitive than computed tomography indetection of LUCAS-CPR related non-dislocated chest fractures. Resuscitation 83:
e89-90, 2012 (level 5)

FigureAn autopsy case of pericardial hematomas due to ruptured dissection of ananeurysm of the thoracic aorta

Confirmed dead without response in attempt at CPR. The right third rib was
dislocated (A, B), here considered a fracture caused by an external force from thefront. The presence of pericardial and mediastinal hematomas and righthemothorax indicated the possibility of traumatic cardiovascular rupture. A
fluid-fluid level in the right pleural cavity (A, arrowheads) indicated the possibilityof blood with fluidity leaking into the cavity. During the autopsy, only a small
amount of hemorrhaged liquid around the fracture was evident (C); however,
evaluation of the extent of the hemorrhage by CT scans was difficult. If thefractures had accompanied a major dislocation, they could have been detected with

volume rendering (VR) images; however, some small fractures were difficult to
detect. As the autopsy showed contusions and lacerations between theintrapericardial aorta at the level of the pericardial reflection and the right hilarparietal pleura (D, arrows), it was considered that the pericardial hematoma had
leaked into the mediastinal connective tissue and the pleural cavity by chest
compression.

CQ26 Is postmortem imaging useful in diagnosing visceral injuries due tocardiopulmonary resuscitation?
Grade of Recommendaton: C2
Postmortem

imagingisusefulindiagnosing

visceralinjuriesduetocardiopulmonary resuscitation (CPR) in case of nontraumatic cardiac arrest.
Previous studies have suggested that intraperitoneal gas introduced by gastricperforation and pneumothorax associated with chest compression could also be
detected by postmortem imaging. In detecting liver and splenic injuries,
postmortem computed tomography (CT) scans with contrast agents is useful.
As the incidence of intraperitoneal hemorrhages associated with liver and spleen
injuries increases after death and may affect the diagnosis of the cause of death, aCT scan immediately after death is recommended.
A small amount of liquid from pericardial or mediastinal hematomas due to chest
compression should not be considered as a cause of sudden death.
Explanation
Because interventions such as chest compression and positive pressure ventilation
are performed during CPR after cardiac arrest, there are many reports of visceralinjuries after the circulation is restored1)2). For thoracic organs, cases such as
cardiac tamponade due to pericardial and cardiac injuries (Figure) and hemothorax
due to lung injuries have been reported. For abdominal organs, cases such as gastricperforation and liver and spleen injuries have also been reported. Cases of mortality
have also been attributed to visceral injuries as a complication resulting fromsurgical procedures, in which hemorrhagic lesions were identified by postmortem
CT scans with a contrast agent3). Overall, postmortem CT scans with a contrast
agent are useful in distinguishing between visceral injuries due to chest
compression and primary visceral injuries due to other causes.
In general, visceral injuries as a complication with chest compression are notaccompanied by massive hemorrhages. A case of traumatic death was reported, inwhich the initial postmortem CT scan obtained immediately after death showed no
massive peritoneal hemorrhage but the autopsy identified a remarkable increase inhemorrhaged volume after the death; therefore, a CT scan immediately after death
is recommended to distinguish between primary antemortem injuries and injuriesassociated with chest compression4).
Research methodology and supplementary materials
The following terms were searched for on PubMed with parameters defined to bewithin the past 10 years: postmortem CT, CPR, injury, complication, and autopsy.
Referenced documents in the resulting articles and other useful papers have also
been cited.
References
1. Meron G et al. Cardiopulmonary resuscitation-associated major
liver injury. Resuscitation 75:445-53, 2007 (level 5)
2. Miller AC et al. A systematic review and pooled analysis of
CPR-associated cardiovascular and thoracic injuries. Resuscitation 85:724-31, 2014(level 5)
3. Zerlauth JB et al. Surgical interventions with fatal outcome:Utility of multi-phase postmortem CT angiography. Forensic Sci Int 225:32-41, 2013(level 5)
4. Miyamori D et al. Temporal evolution in peritoneal hemorrhage as
depicted by postmortem CT. J Forensic Leg Med 20:548-50, 2013 (level 5)

FigureAn autopsy case with a noteworthy secondary injury associated with attempted
CPR

A case of a sudden collapse followed by disturbance of consciousness in front of adentist who visited the patient’s home. Despite an immediate CPR attempt, thepatient was confirmed dead on arrival at the hospital. Postmortem CT scans showed
multiple rib fractures, right pneumothorax, mediastinal shift to the left, left
hemothorax (coagulation), massive hematomas in the muscles of the left chest andback, and subcutaneous emphysema of the right chest (A, B, C). Effusion in theabdominal cavity was also obvious (D), indicating injuries and hemorrhages inabdominal parenchymal organs. During the autopsy, extensive thoracic fractures
were also identified. The right thoracic wall fractures were not accompanied by any
hemorrhage, but a massive hemorrhage was obvious in the muscles of the left
thoracic wall that communicated with the intrapleural space (E). Contusion in theleft lobe of the liver (below the xiphoid process) was evident, and 430 mL of blood
with fluidity was accumulated in the peritoneal cavity. The pericardial membrane
was wide open, and the heart had moved deviated to the left pleural cavity (F)containing 340 mL of coagulated blood. A large laceration from the anterior wall tothe apex of the heart was identified (G, arrowhead), and was pathologicallydiagnosed as a cardiac rupture after myocardial infarction. This remarkablesecondary injury as a complication of a CPR attempt modified thepathophysiological condition at death.

CQ27 Is postmortem imaging useful in diagnosing causes of death during external
examinations of cadavers?

Grade of Recommendation: C1
It is useful to apply postmortem imaging to external examinations of corpses since
the cause of death may be diagnosed with the images inspected.

It may help

determining if there are external cause of death for a corpse. It can also assist in
determining injuries or foreign matter inside the corpse.
However, caution is needed in the interpretation since there are many pathologicalconditions which could be missed by postmortem CT scans.
Explanation
The forensic autopsy rate for unnatural deaths in Japan is approximately 10%,extremely low compared to other developed countries (1,2). If a case is believed to be
due to natural death, not involving anything criminal at the time of inspection by apolice officer or a physician, the body will be cremated without being autopsied (1).
Postmortem imaging is thought to be a useful tool for detecting injuries orpathological conditions which are overlooked by external examinations (1).
Diagnostic rate by postmortem imaging
A study comparing the findings of postmortem imaging and autopsies reported thatthe diagnosis of causes of death with CT scanning alone was 80% in traumaticdeaths and 30% in non-traumatic deaths (2). Hemorrhagic diseases such as cerebral
hemorrhages, subarachnoid hemorrhages, dissection of the aorta and ruptures ofabdominal aortic aneurysms can be diagnosed by postmortem CT scans. The images
should be interpreted by radiologists or forensic pathologists familiar with
postmortem CT scan interpretation through experience in comparing autopsies andCT findings (1).
Preventing overlooked crimes and accidents
In a study by Iwase et al., of 80 cases where the police determined a death as deathby disease with no element of criminality in their initial investigations, externalcauses were shown by postmortem CT scans in 8 cases (10%) (1). A CT scan may be
used as a tool for preventing such overlooked cases of external causes (1).
Postmortem CT scans were found to be useful as a screening and documentation

method for stomach contents in cases where oral medication intoxication isconsidered.
In drug overdose cases, postmortem CT scans can be used as a screening tool. In
non-suspicious cases with common findings and negative external examinations, abasal radio-opaque layer in the stomach of >100 HU is strongly suggestive of an
intentional drug overdose (3). Postmortem CT scans can also identify overlooked
cases of asphyxia by choking since they enable detection of laryngeal foreign
elements invisible by external examination (4-6).
Avoid autopsies in the case of infectious diseases
Some studies report that rapid toxicological tests and care in scanning andinterpreting postmortem CT scans can reduce the number of autopsies helping to
avoid infection from cases of high-risk infectious diseases such as HIV or HCV
positive cases.
Combinations with other examinations
Although the rate of diagnosis of causes of death with CT scanning alone is low (1), a
combination of plain CT scans, postmortem CT angiography, and biopsies,
representing a minimally invasive approach has delivered noteworthy results (7).
Such minimally invasive approaches have led to correct diagnosis of the cause ofdeath in 90% of the studied cases (7). The clinical notes will also help to ensure thatthe post-mortem examination provides the most accurate and comprehensive
information regarding the cause of death (8).
Pathology findings that may be overlooked or invisible by postmortem CT scans
Postmortem imaging findings were not helpful in reaching a definitive diagnosis ofischemic

cardiacdisease,inflammatory entities (1).

chemical

addiction,

metabolicdisorders,andFurther, CT scans may also miss cervical spine injuries,

cardiac ruptures, injuries to hollow organs, diaphragmatic injuries, andhemomediastinum (1). There are some important autopsy findings which have notbeen identified with CT-scanning, including non-calcified severe coronary
atherosclerosis, coronary thrombosis, pulmonary embolisms, bronchiectasis,
emphysema, liver or spleen contusions, severe aspiration/boluses, micronodular
cirrhosis, fractures of the cranial base, chronic gastrointestinal ulceration(duodenum and esophagus) and more (9). There have been unexpected microscopic
findings at autopsies, including microscopic occulted cancers, chronic lymphatic

leukaemia,

disseminatedsarcoidosis,

bronchopneumonias,

andpulmonarytuberculosis (9).
Important CT findings that tend to be missed by autopsies
Important CT findings overlooked at autopsies are fractures (extremities, pelvis,
facial skeleton), pneumothorax, bone metastases, hydrothorax with cardiac
compression, subcutaneous emphysema (9).
Postmortem CT findings of fetuses
At present, the only evidence based use of postmortem MRI scanning as an
adjuvant to autopsies is in cases of fetal brain abnormalities (10).
PubMed 2014/2/25#1

Search (postmortem CT) OR (postmortem computed tomography)#2

Search (causes of death) AND (autopsy)#3

Search (#1) AND (#2)

#4

Search (#3) AND English[Language] Filters: published in the last 10 years

Results 196#5(#4) AND (external examination)検索結果 5#6(#4) AND (choking)検索結果 7

Japanese Medical Library 医中誌（死後 CT）OR（死後画像）検索結果 292
Reference
1. Iwase H, et al: Evaluation of computed tomography as a screening test for deathinquest J. Forensic Sci 55(6):1509–15, 2010 （levelⅤ）
2. Shiotani S, et al: Cause of death screening using postmortem CT and MRI –advantage and disadvantage-. Daiwa Shoken Health Research Report 35:16-20,
2012 （levelⅣ） (Japanese)
3. Burke MP, et al: The use of postmortem computed tomography in the diagnosis ofintentional medication overdose. Forensic Sci Med Pathol 8(3):218–36, 2012 （level
Ⅴ）
4. Oesterhelweg L, et al: Virtopsy: postmortem imaging of laryngeal foreign bodies.
Arch Pathol Lab Med 133(5):806–10, 2009 （levelⅤ）
5. Iino M, et al: Postmortem computed tomography findings of upper airway
obstruction by food. J Forensic Sci 55(5):1251–8, 2010 （levelⅤ）6. Thali Y, et al: Death by biscuit-exhumation, post-mortem CT, and revision of thecause of death one year after interment. Leg Med (Tokyo) 13(3):142–4, 2011 （levelⅤ）
7. Bolliger S, et al: Postmortem imaging-guided biopsy as an adjuvant to minimallyinvasive autopsy with CT and postmortem angiography: a feasibility study. AJR
Am J Roentgenol 195(5):1051–6, 2010 （levelⅣ）
8. Owais AE, et al:Could pre-mortem computerised tomography scans reduce theneed for coroner’s post-mortem examinations? Ann R Col. Surg Engl 92(5):422–4,
2010 （levelⅣ）
9. Leth P M: Computerized tomography used as a routine procedure at postmortem
investigations. Am J Forensic Med Pathol 30(3):219–22, 2009 （levelⅣ）
10. Thayyil S: Less invasive autopsy: an evidenced based approach. Arch Dis Child96(7):681–7, 2011 （levelⅠ）

CQ28 Is it useful to use postmortem radiography before autopsies?

Grades of recommendations: C1 for evaluating the condition
C2 for determining the cause of death

Postmortem CT is useful to record the findings which may disappear by autopsies,
such as the quantity and location of the gas. In addition, the autopsy has difficulty
to investigate whole body bones, but postmortem CT may record it objectively.
According to the operators’ medical safety, postmortem CT is also useful to arrange
facilities / equipment before autopsy in case of high risk infections.
There are cases where findings about bones are useful for identification, such as thebone configurations, or scars from orthopedic surgery. That kind of information
makes a detailed autopsy necessary.
While discussing whether radiological diagnosis will be an alternative method to
conduct the autopsy, there is a further reputation to combine postmortem imaging
with autopsy.

Explanation
There are few documents, which examined whether pre-autopsy post-mortem
imaging is useful or not, and some reports, where it is only described as experience
or comment.
In any case, whole body search with CT scans is useful for detection of gas, bonecomponents, metals, and for other reasons.
1. Whole body CT is useful as pre-autopsy imaging shows findings of irregularly
deformed bullets and their fragments, bone fragments, and infected areas like fortuberculosis. We can prepare the clothes and equipment necessary for autopsy withassurance of safety and quality, and also pay attention during autopsy. (1)2. We can obtain the valuable information about forensic anthropology. (2)3. Postmortem imaging was very useful for investigating many unidentified copses
at forest fires. In burned bodies, it is impossible to examine the external surface,
fingerprints, teeth, and DNA. However, we can get much information from

postmortem imaging, such as skeleton, arteriosclerosis, metal medical material, etc.
In 61% of cases gender could be determined on CT scans. Age range could bedetermined on CT in 94% of cases with an accuracy of 76%. (3)Reference
1. Rutty GN, et al: Accuracy of magnetic resonance imaging in determining cause of
sudden death in adults: comparison with conventional autopsy. Histopathology
44(2) 187-9, 2004 （levelⅣ）
2. Dedouit F, et al: Virtual autopsy and forensic identification-practical application:a report of one case. J Forensic Sci 52(4):960-4, 2007 （levelⅤ）
3. O'Donnell CJ, et al: Contribution of postmortem multidetector CT scanning to
identification of the deceased in a mass disaster: Experience gained from the 2009
Victorian bushfires. Forensic Sci Int 25;205(1-3):15-28, 2011 （levelⅣ）

Figureburning to deathAt the macroscopic investigation, almost all of the arms and feet are lost by burning.
The three cavities: head, chest, and abdomen, are opened, and the organ
investigation is difficult (a). Using CT 3 dimensional imaging, there are sternalbone wires (b,c). For the identification, a person with a history of mitral valve
replacement would be a candidate. The postmortem CT image (d) and clinical chest
XP image (e), those are used to compare the metallic placement, and the wire
shapes match.