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## Complete Summary

#### GUIDELINE TITLE

Suspected lower extremity deep vein thrombosis.

#### BIBLIOGRAPHIC SOURCE(S)

Polak JF, Yucel EK, Bettmann MA, Casciani T, Gomes AS, Grollman JH,
Holtzman SR, Sacks D, Schoepf J, Stanford W, Jaff M, Moneta GL, Expert
Panel on Cardiovascular Imaging. Suspected lower extremity deep vein
thrombosis. \[online publication\]. Reston (VA): American College of
Radiology (ACR); 2005. 5 p. \[44 references\]

#### GUIDELINE STATUS

This is the current release of the guideline.

This guideline updates a previous version: Needleman L, Polak JF,
Bettmann MA, Boxt LM, Gomes AS, Grollman J, Henkin RE, Higgins CB,
Kelley MJ, Pagan-Marin H, Stanford W. Suspected lower extremity deep
vein thrombosis. American College of Radiology. ACR Appropriateness
Criteria. Radiology 2000 Jun;215(Suppl):49-53.

The appropriateness criteria are reviewed annually and updated by the
panels as needed, depending on introduction of new and highly
significant scientific evidence.

### \*\* REGULATORY ALERT \*\*

#### FDA WARNING/REGULATORY ALERT

**Note from the National Guideline Clearinghouse**: This guideline
references a drug(s) for which important revised regulatory and/or
warning information has been released.

-   [May 23, 2007, Gadolinium-based Contrast
    Agents](http://www.fda.gov/medwatch/safety/2007/safety07.htm#Gadolinium):
    The addition of a boxed warning and new warnings about the risk of
    nephrogenic systemic fibrosis (NSF) to the full prescribing
    information for all gadolinium-based contrast agents (GBCAs).

### COMPLETE SUMMARY CONTENT

 \*\* REGULATORY ALERT \*\*\
 SCOPE\
 METHODOLOGY - including Rating Scheme and Cost Analysis\
 RECOMMENDATIONS\
 EVIDENCE SUPPORTING THE RECOMMENDATIONS\
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS\
 QUALIFYING STATEMENTS\
 IMPLEMENTATION OF THE GUIDELINE\
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT
CATEGORIES\
 IDENTIFYING INFORMATION AND AVAILABILITY\
 DISCLAIMER

### SCOPE

#### DISEASE/CONDITION(S)

Lower extremity deep vein thrombosis

#### GUIDELINE CATEGORY

Diagnosis

#### CLINICAL SPECIALTY

Emergency Medicine\
Family Practice\
Geriatrics\
Internal Medicine\
Nuclear Medicine\
Radiology

#### INTENDED USERS

Health Plans\
Hospitals\
Managed Care Organizations\
Physicians\
Utilization Management

#### GUIDELINE OBJECTIVE(S)

To evaluate the appropriateness of initial radiologic examinations for
patients with suspected lower extremity deep vein thrombosis

#### TARGET POPULATION

Patients with suspected lower extremity deep vein thrombosis

#### INTERVENTIONS AND PRACTICES CONSIDERED

1.  Ultrasound (US), Duplex Doppler compression

2.  Magnetic resonance imaging (MRI), venography

3.  Invasive (INV)

    -   Venography, pelvic

    -   Venography, lower extremity

4.  Computed tomography (CT) (as an adjunct to CT pulmonary angiography
    \[CTPA\] for suspected pulmonary embolism \[PE\])

    -   Pelvis, with contrast

    -   Venography, lower extremity, (following arm injection)

5.  Nuclear medicine (NUC), radionuclide venography (macroaggregated
    albumin \[MAA\])

6.  Impedance plethysmography (IPG)

7.  X-ray

8.  Continuous Wave Doppler (nonimaging)

#### MAJOR OUTCOMES CONSIDERED

Utility of radiologic examinations in differential diagnosis

### METHODOLOGY

#### METHODS USED TO COLLECT/SELECT EVIDENCE

Searches of Electronic Databases

#### DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

The guideline developer performed literature searches of peer-reviewed
medical journals, and the major applicable articles were identified and
collected.

#### NUMBER OF SOURCE DOCUMENTS

The total number of source documents identified as the result of the
literature search is not known.

#### METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Weighting According to a Rating Scheme (Scheme Not Given)

#### RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

Not stated

#### METHODS USED TO ANALYZE THE EVIDENCE

Systematic Review with Evidence Tables

#### DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

One or two topic leaders within a panel assume the responsibility of
developing an evidence table for each clinical condition, based on
analysis of the current literature. These tables serve as a basis for
developing a narrative specific to each clinical condition.

#### METHODS USED TO FORMULATE THE RECOMMENDATIONS

Expert Consensus (Delphi)

#### DESCRIPTION OF METHODS USED TO FORMULATE THE RECOMMENDATIONS

Since data available from existing scientific studies are usually
insufficient for meta-analysis, broad-based consensus techniques are
needed to reach agreement in the formulation of the appropriateness
criteria. The American College of Radiology (ACR) Appropriateness
Criteria panels use a modified Delphi technique to arrive at consensus.
Serial surveys are conducted by distributing questionnaires to
consolidate expert opinions within each panel. These questionnaires are
distributed to the participants along with the evidence table and
narrative as developed by the topic leader(s). Questionnaires are
completed by the participants in their own professional setting without
influence of the other members. Voting is conducted using a scoring
system from 1-9, indicating the least to the most appropriate imaging
examination or therapeutic procedure. The survey results are collected,
tabulated in anonymous fashion, and redistributed after each round. A
maximum of three rounds is conducted and opinions are unified to the
highest degree possible. Eighty percent agreement is considered a
consensus. This modified Delphi technique enables individual, unbiased
expression, is economical, easy to understand, and relatively simple to
conduct.

If consensus cannot be reached by this Delphi technique, the panel is
convened and group consensus techniques are utilized. The strengths and
weaknesses of each test or procedure are discussed and consensus reached
whenever possible. If \"No consensus\" appears in the rating column,
reasons for this decision are added to the comment sections.

#### RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

Not applicable

#### COST ANALYSIS

A formal cost analysis was not performed and published cost analyses
were not reviewed.

#### METHOD OF GUIDELINE VALIDATION

Internal Peer Review

#### DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

Criteria developed by the Expert Panels are reviewed by the American
College of Radiology (ACR) Committee on Appropriateness Criteria.

### RECOMMENDATIONS

#### MAJOR RECOMMENDATIONS

**ACR Appropriateness Criteria®**

**Clinical Condition: Suspected Lower Extremity Deep Vein Thrombosis
(DVT)**

  ---------------------------------------------------------------------------
  **Radiologic Exam    **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  US, Duplex Doppler   9                    
  compression                              

  MRI, venography,     6                   Demonstrated to be useful, but
  lower extremity                          insufficient supporting data so
                                           far.

  INV, venography,     6                   When other studies equivocal or an
  pelvic                                   intervention is planned.

  CT, pelvis, with     6                   As an adjunct to CTPA done for
  contrast                                 suspected PE

  INV, venography,     5                   When other studies equivocal or an
  lower extremity                          intervention is planned.

  CT, venography,      5                   As an adjunct to CTPA done for
  lower extremity,                         suspected PE
  (following arm                           
  injection)                               

  NUC, Radionuclide    3                    
  venography (MAA),                        
  lower extremity                          

  IPG, lower extremity 2                    

  X-ray, lower         2                    
  extremity                                

  Continuous Wave      1                    
  Doppler                                  
  (nonimaging), lower                      
  extremity                                

  ***Appropriateness                       
  Criteria Scale*\                         
  1 2 3 4 5 6 7 8 9\                       
  1 = Least                                
  appropriate 9 = Most                     
  appropriate**                            
  ---------------------------------------------------------------------------

Note: Abbreviations used in the table are listed at the end of the
\"Major Recommendations\" field.

The patient with symptomatic acute deep vein thrombosis (DVT) in a leg
vein presents either with local pain and tenderness or with edema and
swelling of the lower extremity, although patients with extensive DVT
may be completely asymptomatic. Accuracy of the clinical diagnosis DVT
is no better than 50%. Some of the pathological entities that mimic the
signs and symptoms of acute DVT are Baker\'s cyst, cellulitis,
lymphedema, chronic venous disease, and varied musculoskeletal
disorders. The importance of diagnosing acute DVT lies mostly in its
relationship to acute pulmonary embolism. Without treatment, pulmonary
embolism is likely to occur in up to 50% of patients who have DVT of the
lower extremity. Up to 30% of the episodes of pulmonary embolism can
have death as an outcome. This can be significantly reduced\--by a
factor of 10\--when the patient is treated with anticoagulation. The
site of DVT is important since involvement of the popliteal and
above-the-knee veins is strongly associated with the risk of pulmonary
embolism. DVT involving only the calf veins is not associated with a
high risk for pulmonary embolism. Symptomatic DVT isolated to the calf
veins is also less common than DVT of the femoropopliteal system.

Various tests that are available for evaluating the patient include
contrast venography, Doppler US, various radionuclide approaches, a
plasma D-dimer test, magnetic resonance venography, and contrast
computed tomographic venography (MRV). Diagnostic tests that have been
discarded include nonimaging Doppler waveform analysis, thermography,
and various iterations of plethysmography: impedance, strain and
photo-plethysmography.

Imaging is a key component of diagnostic strategies used to determine
the presence of lower extremity deep vein thrombosis (DVT). Lower
extremity contrast venography is now rarely used in clinical practice,
although it is still considered to be the \"gold standard\" examination.
Noninvasive tests, with the exception of plasma D-dimer (due to high
sensitivity but limited specificity for DVT), are used with the
following consideration: a patient with a positive result on a
noninvasive test is considered to have DVT and is treated. If the test
gives a negative result, then the clinical suspicion of DVT is used to
determine whether another test or the same test should be used to
serially monitor the patient. If the repeated test becomes positive, the
patient is treated. If the noninvasive test remains negative, it or
another test may be repeated. The type of test, the number of repeat
examinations, and the duration of serial monitoring vary. For example,
patients who have only above-the-knee venous US studies may still have
below-the-knee (calf) deep vein thrombi. A repeat US examination at 5 to
7 days has been proven to reliably diagnose patients with calf vein
thrombi that extend into the above-the-knee veins. If this occurs, the
patient is treated. If the test remains negative, the patient is
considered not to have lower extremity DVT.

**Contrast Venography**

Contrast venography is the \"gold-standard\" examination. An
iodine-containing contrast agent is injected into a foot vein. DVT is
present if a distinct filling defect is present in a deep vein of the
calf or thigh. Other findings, such as an abrupt cutoff, absence of
filling or presence of collaterals, are less specific and may be related
to technical factors or to chronic venous thrombosis. Although this
examination serves as the \"gold standard,\" it may not give reliable
results in 5 to 10% of patients. It also carries some risks: contrast
reaction, local irritation or skin loss due to extravasation, renal
failure, and chemically induced thrombophlebitis.

**Ultrasound Imaging**

Ultrasound is now recognized as the most effective alternative to
contrast venography for the detection of symptomatic venous thrombosis
of the leg. During real-time imaging, the main diagnostic criterion is
failure to compress the vein walls while pressure is applied to the
skin. This approach has a very high sensitivity (95%) and a high
specificity (98%) for the above-the-knee veins. The accuracy for
detecting isolated calf vein thrombosis is not as well studied.
Sensitivity is at least 90% for specificity above 90% if isolated calf
vein thrombi are sought. Doppler waveform analysis is integrated with
imaging US as either duplex US or color flow US. Color Doppler imaging
may also help characterize the type of DVT as obstructive or partly
obstructive. Although continuous-wave Doppler can be used without
imaging, this requires considerable skill. This non-imaging approach has
been supplanted by duplex and color flow imaging techniques. The
real-time US examination is easy to perform, can be done at the bedside,
and can be used for serial studies. It has a low technical failure rate.
It is less consistent in diagnostic performance above the inguinal
canal.

**Tests of Limited Utility**

Plethysmography was for a time considered the main approach to the
noninvasive detection of DVT. It evaluates the filling and emptying
characteristics of blood in the lower extremity veins under resting
conditions and simple physiologic maneuvers (PRG) or during a
standardized protocol (impedance plethysmography). Measurements of blood
volume changes are made with pressure cuffs, strain-gauge meters, or
electrical impedance metering. Its accuracy is not as high as that of
compression US, and it must be performed with meticulous technique.
Also, it does not detect most cases of calf vein thrombosis (sensitivity
of 20 to 30%). Consequently, plethysmography-based techniques are now
rarely used.

Light rheography (photoplethysmography) is a technique that gives a
signal proportional to the blood volume in the subcutaneous tissues. It
uses infrared detectors. It performs poorly for the detection of DVT but
can be used to confirm the presence of venous insufficiency.

Thermography relies on the detection of temperature changes in the limb
to diagnose DVT. It may work well for active superficial
thrombophlebitis, but it has limited utility for most cases of DVT. It
is unlikely that it will identify most patients with nonobstructive DVT.

**Radionuclide Imaging**

There are two approaches to the use of radioactive compounds: imaging of
the vein lumen, and use of radiopharmaceutical complexes that target
thrombi. The vein lumen can be visualized by labeling the blood pool
(i.e., erythrocytes) with Technetium-99m. Acute DVT replaces labeled
blood and causes a loss of blood pool radioactivity. This causes a
defect on the image. This test has an accuracy of close to 90% when
large obstructive venous thrombi are present in the femoropopliteal
veins. A radionuclide venogram can also be performed during the
injection of Tc-99m labeled macroaggregated albumin, typically as part
of a pulmonary perfusion scintigram. Nonvisualization of the vein is
then used as a diagnostic criterion.

There are many approaches to the use of active uptake of a radiolabeled
compound by forming thrombi. Diagnostic tests that rely on this approach
include labeled fibrinogen, platelets, fibrin, and plasmin. They perform
best for DVT located below the knee or in the lower thigh.
Iodine-labeled fibrinogen has long served as a \"gold standard\" with
sensitivity above 80 to 90%, but it is no longer available. Labeled
platelets can also be used. Their sensitivity is low for detecting
thrombi above the knee: this is due to the small amount of radioactivity
that accumulates in the forming thrombus with respect to the amount of
background radioactivity. This can be improved by delayed (24-hour)
imaging. Uptake is also decreased by concurrent anticoagulation. Labeled
antifibrin antibody also suffers from a low signal-to-noise problem that
decreases the sensitivity for detecting thrombi above the mid-thigh.
Labeled plasmin, as reported in the literature, is very sensitive. Its
specificity, however, is poor; the highest reported values for
specificity vary between 60 to 70%.

**Magnetic Resonance Imaging**

Magnetic resonance venography (MRV) has principally been used for
evaluating the pelvic veins. Thrombus shows up either as a venous
segment without flow or as a discrete filling defect in the vein lumen
with a flow-based approach such as time-of-flight or gradient-focused
rapid imaging. The accuracy is high for the pelvic veins, and it is also
reported to be above 90% in the few series studying its application to
the femoro-popliteal system and the calf veins. Contrast enhanced MRI
following the intravenous injection of a gadolinium based complex is
also principally used in evaluating pelvic veins and is rarely used for
the lower extremities. An alternative imaging approach is to use MRI to
directly image thrombus while it is forming. Selective pulse sequences
that highlight the signal in forming thrombi have shown good diagnostic
performance, but diagnostic experience to date has been limited to one
group of investigators. Patients with pacemakers or claustrophobia
cannot tolerate the procedure. MRV is likely to be used when venous
thrombi are located above the inguinal ligament or when extrinsic
compression on the iliac veins mimics the signs and symptoms of DVT.

**Computed Tomographic Venography**

CT can be used to diagnose leg vein DVT. This approach was originally
used for imaging of the iliac veins. It is superior to iliac vein
venography because it can identify sources of extrinsic compression of
the iliac vein as well as diagnose deep vein thrombosis. The technique
does not, however, give the fine anatomic detail of the vein lumen and
may not show evidence of scarring due to previous episodes of DVT. CT
venography in conjunction with CT pulmonary angiography has recently
been investigated for its ability to image the thigh and calf veins.
Delayed (3 minute) imaging shows good diagnostic performance when
compared to contrast venography and ultrasound imaging. One advantage of
the approach is the ability to screen for both DVT and pulmonary
embolism during a single CT examination. The accuracy and cost-efficacy
of this approach have yet to be fully defined.

**Plasma D-Dimer Levels**

Various blood tests are able to detect elevated levels of plasma
D-dimer. This plasma constituent is present when the fibrin from active
thrombus is released. Although very sensitive (above 95%), this test is
very nonspecific (less than 50%), since it indicates that thrombus is
forming, but not where. It has clinical utility since it has a high
sensitivity and the negative predictive value of the test is very high.
It is often used as an initial screening test and in conjunction with US
imaging and CT pulmonary angiography when findings of these studies are
negative despite high clinical suspicion for thromboembolic disease.

**Patients with Suspected Pulmonary Embolism**

The strong linkage between lower extremity DVT and pulmonary embolism
has sometime led to an investigation of the lower extremity veins in
patients suspected of having a pulmonary embolism. The diagnostic yield
of a positive venous US is low, typically less than 10%, in such
patients. More recent data also indicate that the use of follow-up US in
patients with negative CT angiography is low.

**Summary**

The current approach to the evaluation of a symptomatic patient with
suspected acute DVT favors venous US. Other imaging approaches are
either more invasive (contrast venography), less accurate or less
cost-effective for suspected DVT of the femoral or popliteal veins.
Suspected involvement of the iliac veins can be investigated with
venography or CT. Delayed CT venography following an arm vein injection
has shown good reliability as compared to US and venography. MRV is
reliable for the pelvic and thigh veins but has yet to be evaluated in
any large clinical series for evaluating calf veins. Plasma D-dimer
levels are excellent as a screening test in high-risk patients or in the
presence of high clinical suspicion, but a positive result must be
confirmed by other studies, such as CT or US.

Users of these guidelines must take into consideration the recent
recommendation that symptomatic calf vein DVT needs to be treated with
systemic anticoagulation.

**Abbreviations**

-   CT, computed tomography

-   CTPA, CT pulmonary angiography

-   INV, invasive

-   IPG, impedance plethysmography

-   MAA, macroaggregated albumin

-   MRI, magnetic resonance imaging

-   NUC, nuclear medicine

-   PE, pulmonary embolism

-   US, ultrasound

#### CLINICAL ALGORITHM(S)

Algorithms were not developed from criteria guidelines.

### EVIDENCE SUPPORTING THE RECOMMENDATIONS

#### TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The recommendations are based on analysis of the current literature and
expert panel consensus.

### BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

#### POTENTIAL BENEFITS

Selection of appropriate radiologic imaging procedures for evaluation of
patients with suspected lower extremity deep vein thrombosis

**Subgroups Most Likely to Benefit**

Patients with lower extremity deep vein thrombosis, especially involving
the popliteal and above-the-knee veins which are strongly associated
with the risk of pulmonary embolism.

#### POTENTIAL HARMS

Contrast venography carries some risks: contrast reaction, local
irritation or skin loss due to extravasation, renal failure, and
chemically induced thrombophlebitis.

### QUALIFYING STATEMENTS

#### QUALIFYING STATEMENTS

An American College of Radiology (ACR) Committee on Appropriateness
Criteria and its expert panels have developed criteria for determining
appropriate imaging examinations for diagnosis and treatment of
specified medical condition(s). These criteria are intended to guide
radiologists, radiation oncologists, and referring physicians in making
decisions regarding radiologic imaging and treatment. Generally, the
complexity and severity of a patient\'s clinical condition should
dictate the selection of appropriate imaging procedures or treatments.
Only those exams generally used for evaluation of the patient\'s
condition are ranked. Other imaging studies necessary to evaluate other
co-existent diseases or other medical consequences of this condition are
not considered in this document. The availability of equipment or
personnel may influence the selection of appropriate imaging procedures
or treatments. Imaging techniques classified as investigational by the
U.S. Food and Drug Administration (FDA) have not been considered in
developing these criteria; however, study of new equipment and
applications should be encouraged. The ultimate decision regarding the
appropriateness of any specific radiologic examination or treatment must
be made by the referring physician and radiologist in light of all the
circumstances presented in an individual examination.

### IMPLEMENTATION OF THE GUIDELINE

#### DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

#### IMPLEMENTATION TOOLS

Personal Digital Assistant (PDA) Downloads

For information about
[availability](#identifying-information-and-availability), see the
\"Availability of Companion Documents\" and \"Patient Resources\" fields
below.

### INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

#### IOM CARE NEED

Getting Better

#### IOM DOMAIN

Effectiveness

### IDENTIFYING INFORMATION AND AVAILABILITY

#### BIBLIOGRAPHIC SOURCE(S)

Polak JF, Yucel EK, Bettmann MA, Casciani T, Gomes AS, Grollman JH,
Holtzman SR, Sacks D, Schoepf J, Stanford W, Jaff M, Moneta GL, Expert
Panel on Cardiovascular Imaging. Suspected lower extremity deep vein
thrombosis. \[online publication\]. Reston (VA): American College of
Radiology (ACR); 2005. 5 p. \[44 references\]

#### ADAPTATION

Not applicable: The guideline was not adapted from another source.

#### DATE RELEASED

1995 (revised 2005)

#### GUIDELINE DEVELOPER(S)

American College of Radiology - Medical Specialty Society

#### SOURCE(S) OF FUNDING

The American College of Radiology (ACR) provided the funding and the
resources for these ACR Appropriateness Criteria®.

#### GUIDELINE COMMITTEE

Committee on Appropriateness Criteria, Expert Panel on Cardiovascular
Imaging

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

*Panel Members*: Joseph F. Polak, MD, MPH; E. Kent Yucel, MD; Michael A.
Bettmann, MD; Thomas Casciani, MD; Antoinette S. Gomes, MD; Julius H.
Grollman, MD; Stephen R. Holtzman, MD; David Sacks, MD; Joseph Schoepf,
MD; William Stanford, MD; Michael Jaff, MD; Gregory L. Moneta, MD

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

#### GUIDELINE STATUS

This is the current release of the guideline.

This guideline updates a previous version: Needleman L, Polak JF,
Bettmann MA, Boxt LM, Gomes AS, Grollman J, Henkin RE, Higgins CB,
Kelley MJ, Pagan-Marin H, Stanford W. Suspected lower extremity deep
vein thrombosis. American College of Radiology. ACR Appropriateness
Criteria. Radiology 2000 Jun;215(Suppl):49-53.

The appropriateness criteria are reviewed annually and updated by the
panels as needed, depending on introduction of new and highly
significant scientific evidence.

#### GUIDELINE AVAILABILITY

Electronic copies: Available in Portable Document Format (PDF) from the
[American College of Radiology (ACR) Web
site](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/Vascular/SuspectedLowerExtremityDeepVeinThrombosisDoc19.aspx).

ACR Appropriateness Criteria® *Anytime*, *Anywhere*™ (PDA application).
Available from the [ACR Web
site](http://www.acr.org/SecondaryMainMenuCategories/ACRStore/FeaturedCategories/QualityandSafety/ac_pda.aspx).

Print copies: Available from the American College of Radiology, 1891
Preston White Drive, Reston, VA 20191. Telephone: (703) 648-8900.

#### AVAILABILITY OF COMPANION DOCUMENTS

The following is available:

-   ACR Appropriateness Criteria®. Background and development. Reston
    (VA): American College of Radiology; 2 p. Electronic copies:
    Available in Portable Document Format (PDF) from the [American
    College of Radiology (ACR) Web
    site](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/background_dev.aspx).

#### PATIENT RESOURCES

None available

#### NGC STATUS

This summary was completed by ECRI on February 20, 2001. The information
was verified by the guideline developer on March 14, 2001. The summary
was updated by ECRI on March 24, 2006. This summary was updated by ECRI
Institute on May 17, 2007 following the U.S. Food and Drug
Administration (FDA) advisory on Gadolinium-based contrast agents. This
summary was updated by ECRI Institute on June 20, 2007 following the
U.S. Food and Drug Administration (FDA) advisory on gadolinium-based
contrast agents.

#### COPYRIGHT STATEMENT

Instructions for downloading, use, and reproduction of the American
College of Radiology (ACR) Appropriateness Criteria® may be found on the
[ACR Web
site.](http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/ACRAppropriatenessCriteriaTermsandConditionsDoc1.aspx)

### DISCLAIMER

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© 1998-2008 National Guideline Clearinghouse

Date Modified: 11/3/2008