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## Complete Summary

#### GUIDELINE TITLE

Acute pyelonephritis.

#### BIBLIOGRAPHIC SOURCE(S)

Sandler CM, Choyke PL, Bluth E, Bush WH Jr, Casalino DD, Francis IR,
Jafri SZ, Kawashima A, Kronthal A, Older RA, Papanicolaou N, Ramchandani
P, Rosenfield AT, Segal AJ, Tempany C, Resnick MI, Expert Panel on
Urologic Imaging. Acute pyelonephritis. \[online publication\]. Reston
(VA): American College of Radiology (ACR); 2005. 5 p. \[21 references\]

#### GUIDELINE STATUS

This is the current release of the guideline.

It updates a previous published version: American College of Radiology
(ACR), Expert Panel on Urologic Imaging. Imaging in acute
pyelonephritis. Reston (VA): American College of Radiology (ACR); 2001.
4 p. (ACR appropriateness criteria). \[17 references\]

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)

Acute pyelonephritis

#### GUIDELINE CATEGORY

Diagnosis\
Evaluation

#### CLINICAL SPECIALTY

Family Practice\
Internal Medicine\
Nephrology\
Nuclear Medicine\
Pediatrics\
Radiology\
Urology

#### INTENDED USERS

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

#### GUIDELINE OBJECTIVE(S)

To evaluate the appropriateness of radiologic examinations for imaging
in acute pyelonephritis

#### TARGET POPULATION

Patients with acute pyelonephritis

#### INTERVENTIONS AND PRACTICES CONSIDERED

1.  X-ray

    -   Kidney, intravenous urography, intravenous pyelogram (IVP)

    -   Abdomen, kidneys, ureters, bladder (KUB)

    -   Bladder, voiding cystourethrography (VCUG)

    -   Kidney, antegrade pyelography

2.  Ultrasound (US)

    -   Kidney

    -   Renal with KUB

3.  Computed tomography (CT)

    -   Kidney with and without contrast

    -   Abdomen and pelvis, with and without contrast

4.  Nuclear medicine (NUC), kidney, technetium (Tc)-99m
    dimercaptosuccinic acid (DMSA) scan

5.  Magnetic resonance imaging (MRI) kidney

#### MAJOR OUTCOMES CONSIDERED

Utility of radiologic examinations for imaging in acute pyelonephritis

### 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 for reaching 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 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 the 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: Acute Pyelonephritis**

**Variant 1: Uncomplicated patient.**

  ---------------------------------------------------------------------------
  **Radiologic Exam    **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  X-ray, kidney,       3                   Studies show that imaging adds
  intravenous                              little to management if the
  urography, IVP                           patient responds to therapy within
                                           72 hours.

  X-ray, abdomen, KUB  2                   See above.

  X-ray, bladder,      2                   See above.
  voiding                                  
  cystourethrography                       
  (VCUG)                                   

  US, kidney           2                   See above.

  CT, kidney, with and 2                   See above.
  without contrast                         

  CT, kidney, without  2                   See above.
  contrast                                 

  NUC, kidney, Tc-99m  2                   See above.
  DMSA                                     

  MRI, kidney          1                   See above.

  X-ray, kidney,       1                   See above.
  antegrade                                
  pyelography                              

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

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

**Variant 2: Diabetes, immunocompromised.**

  ---------------------------------------------------------------------------
  **Radiologic Exam    **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  CT, abdomen and      8                   Parenchymal and excretory phase.
  pelvis, with and                         
  without contrast                         

  US, renal, with KUB  6                   Somewhat less sensitive than CT
                                           but used preferentially if there
                                           is compromised renal function. KUB
                                           to evaluate stones or air.

  X-ray, kidney,       4                   Normal renal function
  intravenous                              
  urography, IVP                           

  MRI, kidney          4                   For patients who cannot receive
                                           iodinated contrast.

  NUC, kidney, Tc-99m  3                   Cannot differentiate renal
  DMSA                                     parenchymal disease from
                                           perinephric process.

  X-ray, bladder,      2                   Not part of initial evaluation.
  voiding                                  
  cystourethrography                       
  (VCUG)                                   

  X-ray, abdomen, KUB  2                   Insufficient information by itself
                                           to guide therapy.

  X-ray, kidney,       1                   Not an initial study.
  antegrade                                
  pyelography                              

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

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

**Variant 3: Complicated, other (e.g., history of stones, prior renal
surgery, etc.).**

  ---------------------------------------------------------------------------
  **Radiologic Exam    **Appropriateness   **Comments**
  Procedure**          Rating**            
  -------------------- ------------------- ----------------------------------
  CT, abdomen and      8                   Parenchymal and excretory phase.
  pelvis, with and                         
  without contrast                         

  X-ray, kidney,       6                    
  intravenous                              
  urography, IVP                           

  US, renal, with KUB  6                   May be used as an alternative
                                           study to above.

  MRI, kidney          4                    

  X-ray, bladder,      3                   Not part of initial evaluation but
  voiding                                  may be used subsequently to
  cystourethrography                       demonstrate clinically suspected
  (VCUG)                                   reflux.

  NUC, kidney, Tc-99m  3                   Cannot differentiate renal
  DMSA                                     parenchymal disease from
                                           perinephric process.

  X-ray, abdomen, KUB  2                   Insufficient information by itself
                                           to guide therapy.

  X-ray, kidney,       1                   Not an initial study.
  antegrade                                
  pyelography                              

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

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

Inflammatory disease involving the urinary tract is among the most
common infectious disorders affecting humankind. In most adults, the
infection is confined to the lower urinary tract (LUT), the diagnosis is
established by clinical or laboratory studies, and imaging studies are
not required. When the kidney itself is involved or when there is
difficulty in differentiating LUT infection from renal parenchymal
involvement, imaging studies are often requested both for diagnosis and
to plan management. Conditions that are thought to predispose a patient
with LUT infection to renal involvement include vesicoureteral reflux,
altered bladder function, congenital urinary tract anomalies, and the
presence of renal calculi.

Pathologically, inflammatory disease of the kidney generally occurs as
the result of ascending infection from the LUT (whether or not
radiologically demonstrated vesicoureteral reflux is present) by
gram-negative enteric pathogens (usually *Escherichia coli*) and is
known as acute pyelonephritis. This name accurately reflects the
underlying pathologic condition present (i.e., infection involving both
the renal parenchyma and the renal pelvis). In the majority of patients,
uncomplicated pyelonephritis is readily diagnosed clinically and
responds quickly to treatment with appropriate antibiotics. If the
treatment is started late, the patient is immunocompromised, or, for
other poorly understood reasons, small microabscesses that form during
the acute phase of pyelonephritis may coalesce to form an acute renal
abscess. If such an abscess then ruptures into the perinephric space, a
perirenal abscess is formed. If the infection is confined to an
obstructed collecting system, the infection is referred to as
pyelonephrosis. Patients with underlying diabetes are of particular
concern. Not only are they more vulnerable to the development of a
complication from acute pyelonephritis, but it is also more difficult to
establish the diagnosis on clinical grounds in diabetics, since as many
as 50% will not have the typical flank tenderness that helps to
differentiate pyelonephritis from LUT infection in an otherwise healthy
patient.

Prior to the advent of cross-sectional imaging, radiologic studies
performed in patients with uncomplicated pyelonephritis were normal in
most cases. In the early 1970s, however, a subgroup of patients was
identified with acute pyelonephritis, commonly with underlying diabetes,
who did not respond quickly to therapy and in whom urography showed
anatomic and severe functional abnormalities. In order to differentiate
such patients from those with garden-variety pyelonephritis, a new term,
acute bacterial nephritis, was coined. With the advent of
cross-sectional imaging, a whole new lexicon of terminology evolved to
describe various degrees of parenchymal involvement with pyelonephritis.
The Society of Uroradiology has recommended that all patients with renal
infection be referred to as having acute pyelonephritis, with only the
additional modifiers unilateral or bilateral, focal or diffuse, focal
swelling or no focal swelling, and renal enlargement or no enlargement
used to describe the extent of the process.

Traditionally, excretory urography (IVP) has been the primary diagnostic
modality for imaging patients with renal infection. The rationale for
performing urography is not to diagnose acute pyelonephritis but to look
for an underlying anatomic abnormality (i.e., anomaly) that may have
predisposed the patient to the infection; to search for a process such
as a calculus, papillary necrosis, or obstruction that may prevent a
rapid therapeutic response; or to diagnose a complication of the
infection such as a renal or perinephric abscess. As such, many
urologists routinely order an excretory urogram in all patients with
clinical pyelonephritis within the first 24 hours after initiation of
therapy. More recently, CT urography has been increasingly used in place
of IVP.

There is now reasonably good evidence that routine urography does not
alter the clinical care in 90% of patients with pyelonephritis. This
same study showed, however, that if investigation was confined to those
patients who did not become afebrile after 72 hours of appropriate
antibiotics therapy, the number of patients with urographic findings of
immediate clinical significance rose to 36%. The authors also found a
five-fold increase in yield from routine urography in patients with
underlying diabetes or those infected with a pathogen other than
ampicillin-sensitive *Escherichia coli*. Other authors confirmed the
validity of the 72-hour period in a study of the utility of CT in
patients with pyelonephritis; in this series, 95% of patients with
uncomplicated pyelonephritis became afebrile within 48 hours of
appropriate antibiotic therapy, and nearly 100% did so within 72 hours.

There is almost universal agreement that precontrast and postcontrast CT
is the imaging study of choice to diagnose patients with atypical
pyelonephritis or to look for a potential complication of the infection
such as a renal or perinephric abscess or a renal emphysema. In most of
the studies comparing CT with US, much of the superiority of CT lay in
its ability to detect parenchymal abnormalities in patients with
pyelonephritis that are generally missed by US but do not alter the
patient´s therapy. One study, however, reported that US missed 6 of 10
intrarenal and 1 of 5 perinephric abscesses subsequently diagnosed by
CT. In only three of these cases, however, were the results verified by
surgery. The proponents of US are quick to point out its advantages;
namely, low risk, relatively low expense, lack of ionizing radiation,
and, most importantly, the fact that it does not require the use of
contrast material. Recent technical advances in US such as tissue
harmonic imaging and the use of US contrast agents have been shown to
increase the sensitivity of US to subtle parenchymal abnormalities in
pyelonephritis, but further work in this area is needed before definite
recommendations can be made. Conventional gray-scale US has been
considered the method of choice to diagnose pyelonephrosis (i.e.,
low-level echoes within the collecting system), but CT can also suggest
this diagnosis. The most specific test to diagnose pyelonephrosis,
however, is needle aspiration of the collecting system, which is
generally performed as a prelude to percutaneous nephrostomy.

Recently there has been increased interest in the diagnosis of acute
pyelonephritis utilizing technetium 99m DMSA renal scintigraphy,
particularly in children. Recent studies have shown this technique to be
much more sensitive for the detection of pyelonephritis than US.
Recently, Power Doppler ultrasonography has shown sensitivities and
specificities approaching 90% in children with acute pyelonephritis.
This is important in children since differentiating LUT infection from
pyelonephritis is more difficult in the pediatric population and since
it is the young who are more vulnerable to permanent renal damage from
renal inflammatory disease. One recent study, however, suggests that
these benefits do not extend to adults.

Various other imaging studies are of value in selected patients. MRI is
felt to be useful in patients in whom the use of iodinated contrast
material must be avoided, (i.e., those with azotemia or contrast
sensitivity), but case-controlled studies documenting its efficacy have
yet to be published. Recently, gadolinium enhanced inversion recovery
MRI has been shown to be only slightly less sensitive and specific than
DMSA scintigraphy for acute pyelonephritis in children. One potential
disadvantage of MRI is its inability to detect smaller calculi.
Retrograde pyelography is of value in patients with severe infection and
obstruction that cannot be demonstrated noninvasively. Antegrade
pyelography can be used as an alternative to the retrograde study.
Voiding cystourethrography is used to demonstrate vesicoureteral reflux
but is generally only routinely performed in children.

Otherwise healthy patients with uncomplicated pyelonephritis probably
need no radiologic work-up if they respond to antibiotic therapy within
72 hours. If there is no response to therapy, urography is probably the
most cost-effective starting point for evaluation. Diabetics or other
immunocompromised patients should probably be evaluated with precontrast
and postcontrast CT within 24 hours of diagnosis. Ultrasound should be
reserved for patients in whom pyelonephrosis is suspected and those
patients for whom exposure to contrast or radiation is hazardous. All
other adult patients (i.e., males and patients with a history of stones
or other urologic conditions, prior urologic surgery, repeated episodes
of pyelonephritis, etc.) probably deserve early evaluation with
urography.

**Anticipated Exceptions**

The first line study in pregnant patients should be ultrasonography.
Patients with azotemia, pregnancy, suspected vesicoureteral reflux, or
an accelerated clinical course (i.e., sepsis) may all need more
aggressive evaluation.

**Abbreviations**

-   CT, computed tomography

-   IVP, intravenous pyelogram

-   KUB, kidneys, ureters, bladder

-   MRI, magnetic resonance image

-   NUC, nuclear medicine

-   Tc, technetium; DMSA, dimercaptosuccinic acid

-   US, ultrasound

-   VCUG, voiding cystourethrography

#### 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 acute pyelonephritis

**Subgroups Most Likely to Benefit**

-   Immunocompromised patients

-   Diabetic patients

-   Technetium (Tc) 99m dimercaptosuccinic acid (DMSA) renal
    scintigraphy is particularly beneficial in children

-   Patients in whom the use of iodinated contrast material must be
    avoided

-   Patients with severe infection and obstruction

#### POTENTIAL HARMS

-   The ability to detect parenchymal abnormalities in patients with
    pyelonephritis is generally missed by ultrasound (US).

-   One potential disadvantage of magnetic resonance (MR) is its
    inability to detect smaller calculi.

### 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)

Sandler CM, Choyke PL, Bluth E, Bush WH Jr, Casalino DD, Francis IR,
Jafri SZ, Kawashima A, Kronthal A, Older RA, Papanicolaou N, Ramchandani
P, Rosenfield AT, Segal AJ, Tempany C, Resnick MI, Expert Panel on
Urologic Imaging. Acute pyelonephritis. \[online publication\]. Reston
(VA): American College of Radiology (ACR); 2005. 5 p. \[21 references\]

#### 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 Urologic Imaging

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

*Panel Members*: Carl M. Sandler, MD (*Principal Author*); Peter L.
Choyke, MD; Edward Bluth, MD; William H. Bush, Jr, MD; David D.
Casalino, MD; Isaac R. Francis, MD; S. Zafar H. Jafri, MD; Akira
Kawashima, MD, PhD; Alan Kronthal, MD; Robert A. Older, MD; Nicholas
Papanicolaou, MD; Parvati Ramchandani, MD; Arthur T. Rosenfield, MD;
Arthur J. Segal, MD; Clare Tempany, MD; Martin I. Resnick, MD

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

#### GUIDELINE STATUS

This is the current release of the guideline.

It updates a previous published version: American College of Radiology
(ACR), Expert Panel on Urologic Imaging. Imaging in acute
pyelonephritis. Reston (VA): American College of Radiology (ACR); 2001.
4 p. (ACR appropriateness criteria). \[17 references\]

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/ExpertPanelonUrologicImaging/AcutePyelonephritisDoc3.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 May 6, 2001. The information was
verified by the guideline developer as of June 29, 2001. This summary
was updated by ECRI on September 7, 2004. The updated information was
verified by the guideline developer on October 8, 2004. This summary was
updated by ECRI on February 6, 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

#### NGC DISCLAIMER

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© 1998-2008 National Guideline Clearinghouse

Date Modified: 11/3/2008