Noninvasive Assessment of Abdominal Aortic Aneurysm (AAA) Wall Structural Integrity and Inflammation as Predictors of Expansion and/or Rupture
Phase: PHASE4
Conditions: Abdominal Aortic Aneurysm (AAA)
Sponsor: Washington University School of Medicine

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Noninvasive Assessment of Abdominal Aortic Aneurysm 
Wall Structural Integrity and Inflammation as Predictors 
of Expansion and/or Rupture 
 
NCT 03231397 
 
Unique Protocol ID:  201702141 
 
Principal Investigator: Sean J English, MD. 
 
 
Protocol Version: 02 
 
 
Version date:  10/04/2018 
 
 
 
 

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Protocol Title: Noninvasive Assessment of Abdominal Aortic Aneurysm Wall Structural  
Integrity and Inflammation as Predictors of Expansion and/or Rupture 
 
 
Principal Investigator: Sean J English, MD. 
Protocol Version: 02 
Version date:  10/04/2018 
 
 
I. 
BACKGROUND AND SIGNIFICANCE 
Abdominal aortic aneurysm (AAA) is a significant medical problem, with a high mortality rate, 
accounting for approximately 150,000 hospital admissions per year. AAA is the 10th leading cause 
of death in Caucasian men, ages 65 - 74 years, and has accounted for nearly 16,000 deaths overall.1 
Necropsy studies from the United States and Europe suggest an overall prevalence for AAA of 2-
4% for men and 1-2% for women.2,3 Population based screening studies demonstrate a prevalence 
of approximately 9% in men and 2% in women.4 It has been demonstrated that the prevalence of 
AAA increases with increasing age, with an increased prevalence in males compared to females. 
Noninvasive screening in the elderly population has led to an overall increased incidence of 
asymptomatic AAA.2,3,4,5 Currently, 35,000 to 40,000 aneurysms are treated surgically in the 
United States.6 Once AAA formation has commenced, aneurysms will continue to grow at a 
variable rate, until they ultimately rupture. AAA rupture is associated with very high morbidity 
and mortality.  Perioperative mortality rates of approximately 45% have been reported for open 
AAA repair in the United States since the late 1980s.7 Approximately 60% of patients with 
ruptured AAA die before reaching the hospital,8 and emergency open surgical repair carries a 
mortality rate of 35-70%.9 The incidence of AAA rupture continues to increase despite aggressive 
attempts to screen at-risk populations.10,11,12 Improvements in early aneurysm detection and 
surveillance are necessary to decrease the incidence of AAA rupture and associated mortality.13 
 
It is believed that AAA rupture occurs when the aortic wall stress exceeds the tensile strength of the 
degenerated AAA wall. Finite element analysis (FEA) may be utilized to implement biomechanical 
principles in an effort to assess AAA expansion and/or rupture risk.14,15,16,17  Efforts have been made 
to include intraluminal thrombus (ILT) and the anisotropic AAA tissue behavior into the computer 
models of AAAs. AAA rupture occurs when the stress acting on the AAA wall exceeds its strength; 
therefore, the prediction of AAA rupture must include wall stress and strength distributions. 
Considering this, rupture potential index (RPI) is defined as the ratio of the acting wall stress to 
the wall strength, and the maximum RPI for AAA represents its rupture risk. Comparing peak 
stresses and strains using anisotropic and isotropic constitutive relations, we have demonstrated 
significant increases in peak stress when using the anisotropic relationship.18 Considering ruptured 
AAA patients (N=8) and non-ruptured AAA patients (N=4), we have demonstrated a significant 
decrease in AAA wall strength of those AAAs that went on to rupture. The differences in RPI 
values did not reach statistical significance, when comparing ruptured and non-ruptured AAAs; 
however, our initial data suggests that peak RPI may serve as a better predictor of AAA rupture 
than maximum diameter or peak wall stress alone.19  
 
It is hypothesized that the final event leading to aortic rupture involves the degradation of collagen 
within the media, extending out through the adventitia. This occurs through a catalytic process 
induced by inflammatory cells in the aortic wall. Macrophages and neutrophils are a major source 

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of key enzymes at play, particularly serine proteases and matrix metalloproteinases, and are 
believed to play a critical role in this tissue degradation.20 Inflammation of the vascular wall related 
to phagocytic macrophage activity can be demonstrated by increased uptake of 2-deoxy-2-
[18F]fluoro-D-glucose (18F-FDG) PET in the arterial wall.21 Accordingly, 18F-FDG PET has been 
used to assess AAA wall inflammation,22 and increased 18F-FDG uptake has been identified in 
symptomatic AAAs (pain on palpation of AAA) and with rapid aortic enlargement.23 Considering 
symptomatic AAA patients (N=3), Reeps et al. demonstrated significantly increased 18F-FDG 
AAA uptake that correlated with greater macrophage populations on AAA wall histology, as well 
as higher MMP9 expression and decreased collagen fiber content, when tissue was taken at the 
time of repair.24 In a follow-up manuscript, Reeps et al. demonstrated the ability to discriminate 
between symptomatic (N=5) and asymptomatic (N=18) AAA patients on the basis of 18F-FDG 
uptake. They then correlated this increased 18F-FDG uptake with aortic wall macrophage 
infiltration and MMP9 expression.25 We have reviewed 18F-FDG PET scans for AAA patients at 
a single institution compared with those of atherosclerotic, non-aneurysmal aortas and 
demonstrated significantly greater global 18F-FDG uptake by AAAs.26 Utilizing the porcine 
pancreatic elastase (PPE) exposure model in rats stimulated to rupture with β-aminopropionitrile 
(BAPN) exposure, we have demonstrated the ability of 18F-FDG microPET to identify 
metabolically active sites in a pre-rupture state that ultimately rupture.27  
 
Translocator protein (TSPO), formerly referred to as peripheral benzodiazepine receptor, is an 18-
kDa outer mitochondrial protein highly expressed in phagocytic inflammatory cells, such as 
macrophages in the periphery and macrophage-like microglial cells in the central nervous system. 
It has been demonstrated that other inflammatory cells including neutrophils, B cells, natural killer, 
as well as CD4- and CD8-positive cells express TSPO to varying degrees.28 The TSPO radioligand 
11C-PBR28 ([methyl-11C]N-acetyl-N-(2-methoxybenzyl)-2-phenoxy-5-pyridinamine) has been 
used for neuroimaging with primates  and humans, as well as imaging lung injury in humans.29,30 
Other TSPO radioligands, including 11C-PK1195, have been utilized to evaluate macrophage 
presence and behavior in rodent and human carotid plaques.31,32 
 
We have previously demonstrated the utility of 18F-FDG and 11C-PBR28 to study inflammation 
associated with the PPE model of AAA development in rats, thereby verifying similar 18F-FDG 
imaging characteristics in this model compared to humans.33 In conjunction with increased TSPO 
gene expression and protein expression in AAA, this data supports the potential role of 18F-FDG 
and TSPO radioligands for the assessment of aortic wall inflammation during the development of 
aortic aneurysms in patients. Based on macrophage uptake and autoradiographic findings, as well 
as the natural history of AAA rupture, we are seeking to explore the uptake and distribution of 
TSPO radiotracers compared to 18F-FDG and the potential of 11C-PBR28 for the prediction of 
AAA expansion and/or rupture.  This is the first study to assess the use of 11C-PBR28 to confirm 
the work we have performed in rat models of AAA expansion and rupture. The goal of this project 
at this point is not to change current subject management, but we plan to establish the groundwork 
that will serve as a basis for a larger scale study in the future. 
 
 
 
II. 
SPECIFIC AIMS 
The aim of this project is to assess the ability of three different imaging techniques to determine 

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abdominal aortic aneurysm (AAA) rupture risk individually and in concert. Currently, the primary 
factor considered for risk of human AAA rupture is aortic diameter; however, it is well documented 
that small AAAs (<5cm) rupture, while many large AAAs (>8cm) are incidentally discovered. 
Thus, there is no absolute diameter threshold at which AAAs rupture. Approximately 60% of 
patients with ruptured AAA die before reaching the hospital, and emergency open surgical repair 
carries a mortality rate of 35-70%. This suggests that a new diagnostic modality must to be 
developed to reliably predict AAA rupture risk.  
 
We will image subjects with atherosclerotic, non-aneurismal aortas as a control group. We will 
also image smaller, surveillance size (3.0-4.5cm) AAAs, AAAs that will undergo treatment 
(female >5.0cm, male >5.5cm), as well as rapidly expanding AAAs (>0.5cm over 6 months and/or 
>1.0cm over 12 months). The assessment of AAA wall structural integrity by FEA, generated 
utilizing CTA, will be studied in the context of increased metabolic activity and inflammation 
determined by 18F-FDG and 11C-PBR28 PET. We hypothesize that areas of increased 18F-FDG 
and 11C-PBR28 uptake will correlate; however, areas of more discrete, focal 11C-PBR28 uptake 
will correlate with areas of greatest RPI and decreased strength in the AAA wall, and this will be 
most pronounced in rapidly expanding AAAs. However, we also hypothesize that a fraction of 
smaller AAAs will exhibit a similar pattern, demonstrating areas of increased metabolic activity 
and inflammation that are at increased risk of expansion and/or rupture, independent of size or 
diameter.  
 
Aim 1. Perform coregistered, FEA, as well as 18F-FDG and 11C-PBR28 PET of the infrarenal aorta 
using PET-CTA.  
 
Approach. Consider a rapidly expanding AAA group that will demonstrate changes in the 
structural integrity and inflammatory cascade within the AAA wall validating a current approach 
to AAA treatment. Consider a surveillance group of AAA subjects that will demonstrate the ability 
of FEA as well as 18F-FDG and 11C-PBR28, to identify those subjects that are at increased risk of 
AAA expansion and/or rupture, independent of size. 
 
Aim 2. Compare patterns of decreased aortic strength with patterns of increased stress and 
inflammation across three subject groups to determine the appropriateness of expanding these 
analyses to a larger group of clinically relevant subjects. 
 
Approach. Utilizing evolving software to evaluate the same aortic volume across data sets, we 
will compare areas under greatest stress and lowest strength determined by FEA. Multiplanar and 
volumetric analyses of co-registered, FEA as well as 18F-FDG and 11C-PBR28 PET images will 
also be performed. With direct co-registration of the data sets for each subject, qualitative 
comparisons will be made regarding areas of 18F-FDG and 11C-PBR28 uptake, as well as stress, 
strength, and RPI. 
 
 
III. 
SUBJECT SELECTION 
Twenty-four subjects will be recruited for this study. Six control subjects (three males and three 
females), will be considered. Control subjects will have known atherosclerosis by standard clinical 
criteria, without aneurysmal disease. Six subjects (three males and three females) with small AAAs 

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(diameter 3.0-4.5cm), six subjects (three males, AAA >5.5cm and three females, AAA >5.0cm) 
with AAAs that are indicated for treatment, and six subjects (three males and three females) with 
rapidly expanding AAAs (>0.5cm over 6 months and/or >1.0cm over 12 months) will be 
considered. During a clinical visit, the treating physician will introduce the study to each subject, 
and the study coordinator will provide a comprehensive description and materials to the subject. 
 
Subjects 45 years of age or older will be considered and subjects from any at-risk populations (e.g.: 
cognitively impaired persons, prisoners) will not be included. A subject will not be eligible for 
inclusion if any exclusion criteria for PET-CTA apply. Any woman of childbearing age, who is 
planning to become pregnant, is breastfeeding, and/or suspects she may be pregnant, will not be 
enrolled in the study. 
A subject will not be eligible for inclusion in this study if any of the following criteria apply: 
- 
less than 45 years of age; 
- 
pregnant or breastfeeding; 
- 
any greater than normal potential for cardiac arrest; 
- 
Renal disease – defined as eGFR < 60mg/ml/1.73m2 
- 
claustrophobic reactions and/or is unable to lie comfortably on a bed inside the scanner for 
60 minutes as assessed by physical examination and medical history (e.g. back pain, 
arthritis); 
 
A TSPO polymorphism has been previously demonstrated, and quantitative interpretations of 
signal can be confounded by interindividual variability in binding affinity.34 To avoid this 
confounder, we will perform Ala147Thr TSPO polymorphism genotyping as part of the screening 
process.  Those subjects identified as mixed affinity or high affinity from the genetic testing results 
will continue with PET-CTA imaging.  Those subjects who are identified as low affinity will be 
considered screen failures and will not have PET-CTA scanning performed. 
 
Eligibility will be determined by a screening interview and review of the medical record. All 
subjects recruited for the study will be able to withdraw from the study at any time. 
 
 
IV. 
SUBJECT ENROLLMENT 
Subjects scheduled for a vascular surgery clinic visit who fulfill the eligibility criteria will be 
identified through the patient appointment log.  
 
The clinicians will introduce the study to the subject during a clinic visit and will obtain permission 
from the potential subject to be approached by study staff.  Subjects will then be approached in 
person (ideally, and whenever possible) by a study coordinator to undergo consent and schedule 
the study.  At this time, subjects will be informed that the PET-CTA scanning session will be 
performed on the BJH main campus.  
 
The subjects will be informed about the PET-CTA scans, including that these scans will have no 
benefit or impact on their management as well as the risks associated with receiving Iopamidol, a 
regularly used CTA contrast agent, as well as 18F-FDG and 11C-PBR28, the two radiotracers being 
studied.  
 

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Informed consent will be obtained from the subjects by a member of the study team prior to 
obtaining the TSPO polymorphism genotyping blood sample and before the imaging session.  The 
study team member obtaining consent will explain the purpose of the study and its potential 
benefits to society at large. The protocols for the scans will be explained in detail. Subjects will be 
informed about potential risks and benefits of PET-CTA and that the scans will have no benefit or 
impact on their management. Subjects will be informed that they may withdraw from the study at 
any time, for any reason. They will be informed that their refusal to participate in the study or 
choosing to terminate participation at any point will have no influence on their future care and 
treatment.  Study subject information will be protected under HIPAA guidelines.   
 
All subjects will receive a one-time $200 remuneration following completion of the study required 
PET-CTA scans.  All subjects will also be offered parking validation for BJH main campus 
parking. 
 
 
V. 
STUDY PROCEDURES 
Subjects who have not had an eGFR blood test performed within the previous 90 days will have 
approximately 10 ml or 2 teaspoons of blood drawn for creatinine testing prior to the scan being 
performed. 
 
Subject Screening - Subjects will be recommended by their treating physician for the study during 
a clinic visit. The study team member obtaining consent will reinforce with the subjects that 
participation is voluntary and any decision not to participate will not in any way affect their care, 
now or in the future. If the subject chooses to participate, the study team member will obtain 
written informed consent. Any woman of childbearing age, who is seeking to become pregnant, is 
breastfeeding, or who suspects she may be pregnant, will not be enrolled in the study. 
As part of subject screening a genetic test (Ala147Thr TSPO polymorphism genotyping) will be 
performed. During enrollment subjects will be informed about the genetic testing for study 
eligibility. If subjects decide to be part of the study and sign the consent, blood will be drawn by 
the study coordinator.  Only those subjects identified as mixed affinity or high affinity from the 
genetic testing results will continue with PET-CTA imaging.  Those subjects who are identified as 
low affinity will be notified by the study team and will not have PET-CTA scanning performed.  
Participation in the study will end for the low affinity subjects following the genetic testing. 
 
Any female subject of child bearing potential will have a serum or urine pregnancy test the day of 
the PET scans. 
 
Any subject under 45 years-old will not be enrolled in this study. No third parties will assist with 
recruitment of eligible subjects for this protocol.  
 
 
Imaging Details: 
Positron Emission Tomography (PET)- Computed Tomography Angiography (CTA) – 
Eligible participants will undergo 18F-FDG and 11C-PBR28 PET-CT and contrast-enhanced CTA 
imaging performed on the Siemens Biograph 40 PET-CT scanner.  All participants will be studied 
after at least 12-16 hrs of fasting.  Subjects will be positioned for maximum comfort on the imaging 

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table, supine and arms resting above the head or across the chest out of the field of view.  PET 
imaging will begin with 11C-PBR28.  A dosage range of 10-20 mCi is planned.  A low-dose CT 
attenuation scan of the abdomen and pelvis will be acquired for subsequent correction of photon 
attenuation.  Each subject will receive a single intravenous bolus injection of the maximum 
planned dosage of 20 mCi diluted with normal saline up to a total of 20 mL.  The imaging 
acquisition over the aneurysm site will begin immediately with a ~20-minute dynamic imaging 
scan.  At the end of this imaging scan a 20 min static scan will be performed in the adjacent 
abdominal or pelvic site (to serve as a reference location). Subject will remain in the scanner for 
the FDG injection and CT angiography.  Subjects will receive an intravenous bolus injection of 10 
mCi of 18F-FDG followed by a 90-minute period prior to reimaging. Next, subjects will receive a 
standard dose of the Iopamidol contrast agent (50cc) followed by CTA imaging of the abdomen 
and pelvis using standard acquisition parameters to identify the arterial region of interest (ROI) to 
determine the blood input function.  At the end of the CTA imaging scan, subjects will be removed 
from the scanner to rest in an uptake room to allow for the decay of 11C-PBR28.  Subjects will be 
asked to use the restroom to empty their bladder after being removed from the scanner after the 
CTA imaging and again prior to being repositioned on the imaging table for the FDG scan.  A 
second low-dose CT attenuation will be performed with subsequent ~20-minute dynamic imaging 
acquisition for FDG.  The entire imaging session, including both PET and CT acquisitions, will 
last up to approximately three hours. The CTA images will be used to identify the arterial region 
of interest (ROI) for use in determining the blood input function.  
 
Aortic wall 11C-PBR28 and 18F-FDG uptake will be considered in terms of standard uptake values 
(SUV) considering the infrarenal abdominal aorta from the crossing of the left renal vein to the 
iliac bifurcation.  Voxel-wise SUV values over the AAA will be qualitatively assessed across 
subjects and groups.  Maximum (SUVmax) and mean (SUVmean) values normalized to the blood 
pool and non-aneurysmal thoracic aorta will also be considered.  SUVmax and SUV mean values 
associated with areas of focal uptake will also be considered and compared across subjects and 
groups using a Students t-test, with P = 0.05 indicating significance. 
 
Image Evaluation: 
Images will be evaluated by an experienced vascular surgeon, who will only evaluate the infrarenal 
abdominal aorta. Other organs and anatomic structures in the field of view will be evaluated by a 
radiologist on the study team for incidental findings. 
 
While there is some subjectivity in the manner by which a region of interest (ROI) is determined 
for image analysis, this study may not be blinded between control and experimental subjects, as 
control subjects will have non-aneurysmal aortas. However, the analyzing vascular surgeon will 
be blinded to whether a subject has a small versus a rapidly expanding AAA. 
 
FEA Interpretation: 
FEA will be performed by Dr. David Vorp’s group at the University of Pittsburgh.  PET-CTA 
scans performed for the study will be copied onto CD, labeled with a study ID only and mailed by 
a member of the Washington University Study team.  No PHI will be provided to University of 
Pittsburgh. The PET-CTA scans and FEA performed by Dr. Vorp’s laboratory at the University 
of Pittsburgh will be saved for possible future analysis or data presentation. 
 

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VI. 
BIOSTATISTICAL ANALYSIS 
 
This is an exploratory (hypothesis generating) study.  Subject Maximum transverse diameters, 
mean and peak wall stresses, mean and minimum wall strengths, and mean and peak RPI values 
will be compared between groups using a Students t-test, with P < 0.05 indicating significance. 
Aortic wall 11C-PBR28 and 18F-FDG uptake will be considered in terms of standard uptake values 
(SUV) considering the infrarenal abdominal aorta from the crossing of the left renal vein to the 
iliac bifurcation. Voxel-wise SUV values over the AAA will be qualitatively assessed across 
subjects and groups. Maximum (SUVmax) and mean (SUVmean) values normalized to the blood 
pool and non-aneurysmal thoracic aorta will also be considered.  SUVmax and SUVmean values 
associated with areas of focal uptake will also be considered and compared across subjects and 
groups using a Students t-test, with P < 0.05 indicating significance. Multiplanar and volumetric 
analyses of coregistered FEA, with 11C-PBR28 and 18F-FDG PET images will also be performed. 
With direct coregistration of the data sets for each subject, qualitative comparisons will be made 
regarding areas of 11C-PBR28 and 18F-FDG uptake, stress, strength, and RPI. Quantitatively, 
correlations of each data set per subject will be determined. 
 
There will be experimental and control group analysis by comparing subject demographics and 
aortic image measures. ANOVA with post hoc analyses will be performed to compare the groups. 
 
Power Calculation:  
From clinical experience, we expect total 24 subjects, approximately six subjects (3 men and 3 
women) with small AAA size that will continue to undergo surveillance (3.0-4.5cm), six subjects 
(3 men and 3 women) with AAAs that will undergo treatment, and six subjects (3 men and 3 
women) with rapidly expanding  AAAs (>0.5cm over 6 months and/or >1.0cm over 12 months). 
Control group will be consist of 6 subjects (3 men and 3 women) with known atherosclerosis, by 
nature of carotid stenosis and no aortic aneurismal dilation.  Since  this is an exploratory study, 
there is no definite power calculation  for qualitative measures but quantitative analysis  for 
continues variables, to reach a power of 0.80 with confidence level of 95% at alpha level of 0.05, 
there are approximately 10 subjects are needed per group. This is a small exploratory study, and 
we will limit the subject enrollment to six subjects per group due to the financial reasons. 
 
Statistical analysis will be performed using the SAS statistical package (SAS Institute Inc., Cary, 
NC).  
 
Specific Data Variables 
• Demographic/Social 
• Age, sex, race, smoking status 
• Clinical 
• Height, weight, BMI 
• History of DM, HTN, CAD, COPD, CKD, CHF 
• Medication history (including current medications) 
• Hemodynamic laboratory results 
• Procedural 
PET image measures, FEA image measures 

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VII. 
RISKS AND DISCOMFORTS 
  
Risks of PET-CT: 
Subjects participating in this study who undergo PET-CTA, will be exposed to radiation from 
PET-CTA scans of the abdomen and pelvis. Please note that this radiation is not necessary for the 
subject’s medical care and is for research purposes only. 
 
This study will expose subjects to radiation from PET-CTA scans of the abdomen and pelvis and 
from the radiotracers 11C- PBR28 and 18F-FDG. For 11C-PBR28 a dosage range of 10-20 mCi is 
planned.  The Effective Dose for cumulative and maximal radiation dosimetry is 2.42 rem and 
2.73 rem, respectively.  This includes a single intravenous injection of the maximum planned 
administered dosage of 20 mCi of 11C-PBR28 and 10 mCi of 18F-fludeoxglucose plus two low-
dose CTAC scans with topogram and contrast-enhanced CTA imaging of the abdomen and pelvis.  
Maximal Radiation Dosimetry includes one additional low-dose CTAC scan with topogram for 
subjects who undergo a make-up study in the event of technical difficulties due to cyclotron 
radiopharmaceutical failure or with the PET-CT scanner.   
 
If a subject is pregnant or breastfeeding they may not participate in this research study. 
 
Since the effects of radiation can be cumulative, it is important to know of past research related 
radiation exposure. If the subject has participated in other research studies in the past 12 months 
that have involved radiation exposure, they will be asked to inform the investigators or study staff.  
If it is determined that the subject’s prior radiation exposure exceeds our current guidelines, it is 
possible that they will not be allowed to participate in this study. 
 
 
Risks of the Radiotracers 11C-PBR28 and 18F-FDG: 
There are no known side effects to these radioactive dyes.  FDG is approved by the FDA and is 
used daily across the United States. 11C-PBR28 is an investigational radioactive drug. An 
investigational drug is one that has not been approved by the U.S. Food and Drug Administration 
(FDA). This means that PBR28 can only be used in research studies. 
 
There are no known pharmacological risks or side effects of receiving 11C-PBR28 at the dose 
subjects will receive. However, as with any drug, an allergic reaction can occur. Allergic reactions 
can be mild or serious, and can even result in death in some cases.  Common symptoms of an 
allergic reaction are rash, itching, skin problems, swelling of the face and throat, or trouble 
breathing.  Subjects will be instructed to notify study staff right away if they think they are having 
an allergic reaction.   
 
18F-FDG is a type of radiation emitting product that may increase an individual’s risk of cancer. 
We use the smallest dose necessary for imaging and ensure safety during injection.   
 
Risks of the IV: 
Placing an IV catheter into the arm may cause some pain, discomfort, bruising, bleeding, swelling, 
and redness in that area. There is a slight risk of infection which can be treated, temporary loss of 
pulse at the wrist, and fainting.  There may be bruising, pain or discomfort for 2-3 days after the 

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IV catheter is removed.  Rarely, an infection may occur at this site, and if infection does occur, it 
will be treated appropriately. A urine or serum blood (about 2 teaspoons) of blood may be taken 
during this study for pregnancy test, if required.   
 
Risks of Iopamidol Dye: 
Rare side effects from the contrast dye Iopamidol include: 
- 
Nausea (up to 2 in 100 of people).  
- 
Hives (itchy red bumps on the skin, < 1 in 100 people) 
- 
Severe allergic reaction, which can be life threatening (very rarely happens, < 1 in 100,000 
people).  If you have any signs of allergic reaction, we will treat you immediately. 
 
Allergic reactions can be mild or serious, and can even result in death in some cases. Common 
symptoms of an allergic reaction are rash, itching, skin problems, swelling of the face and throat, 
or trouble breathing.  Subjects who think that they are having an allergic reaction, should notify 
the study physician immediately.  If they are having trouble breathing, they should tell the study 
physician immediately.  If experiencing any swelling of the face and/or throat, and/or experiencing 
any trouble breathing after leaving the imaging center, they should call 911 immediately and seek 
medical assistance.  
 
Risks of Unexpected Findings: 
We are performing PET-CTA scans in this study to answer research questions, not as part of the 
medical care.  The information created by this study will not become part of the subject’s hospital 
record.  The PET-CTA scans are not the same as a scan that another physician would order.  It 
may or may not demonstrate anatomy/pathology that would be found on standard PET or CTA 
scans.  
 
The imaging studies performed for this study are for research purposes only. We will only evaluate 
the infrarenal abdominal aorta. Other organs and anatomic structures in the field of view will be 
evaluated for incidental findings by a radiologist on the study team.   
 
 
VIII. POTENTIAL BENEFITS 
 
There is no expected direct benefit for subjects taking part in this study.   Results of this study may 
contribute to prevention of AAA rupture in the future. 
 
IX. 
MONITORING AND QUALITY ASSURANCE 
Any unanticipated problems and adverse events involving risk to human subjects will be reviewed 
by the Principal Investigator and will be reported to the Human Research Committee and the BJH 
RDRC, within the required time frame and to all participating investigators by the PI, according 
to the Human Research Protection Office guidelines. 
 
The imaging techniques utilized for this study are all FDA approved.  Each scanner has a built-in 
monitoring system that automatically shuts down the scanner, if parameters exceed safe levels.  In 
addition, imaging technicians constantly monitor the subjects’ physiologic status and quality of 
the raw data.  
 

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Subject data will be stored on a secure, limited-access, password protected, WU network shared 
drive. Access will be granted to members of the study team. If any new investigator is added to 
the protocol and approved by the IRB, the PI will provide network access to that specific 
investigator. 
 
Data entry will be done by the research coordinator /research nurse weekly and will be monitored 
by the PI.   
 
 
PROJECT TIMELINE 
Objective 
Months 1-8 
Months 9-10 
Months 11-12 
Perform coregistered FEA with /18F-
FDG &  11C-PBR28  PET  
 
 
 
Compare patterns of decreased aortic 
strength with patterns of increased stress, 
RPI, and inflammation 
 
 
 
 
Finalization of data analysis and abstract 
submission 
 
 
 
 
 
X. 
REFERENCES 
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