This is the current release of the guideline.

This guideline updates a previous version: Lorenz JM, Funaki BS, Ray CE Jr, Brown DB, Gemery JM, Greene FL, Kinney TB, Kostelic JK, Millward SF, Nemcek AA Jr, Owens CA, Reinhart RD, Rockey DC, Silberzweig JE, Vatakencherry G, Expert Panel on Interventional Radiology. ACR Appropriateness Criteria® percutaneous catheter drainage of infected fluid collections. [online publication]. Reston (VA): American College of Radiology (ACR); 2009. 8 p.

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

Infected fluid collections

To evaluate the appropriateness of percutaneous catheter drainage and other interventions for the treatment and management of infected fluid collections

Patients with infected fluid collections

Literature Search Procedure

The Medline literature search is based on keywords provided by the topic author. The two general classes of keywords are those related to the condition (e.g., ankle pain, fever) and those that describe the diagnostic or therapeutic intervention of interest (e.g., mammography, MRI).

The search terms and parameters are manipulated to produce the most relevant, current evidence to address the American College of Radiology Appropriateness Criteria (ACR AC) topic being reviewed or developed. Combining the clinical conditions and diagnostic modalities or therapeutic procedures narrows the search to be relevant to the topic. Exploding the term "diagnostic imaging" captures relevant results for diagnostic topics.

The following criteria/limits are used in the searches.

1. Articles that have abstracts available and are concerned with humans.
2. Restrict the search to the year prior to the last topic update or in some cases the author of the topic may specify which year range to use in the search. For new topics, the year range is restricted to the last 5 years unless the topic author provides other instructions.
3. May restrict the search to Adults only or Pediatrics only.
4. Articles consisting of only summaries or case reports are often excluded from final results.

The search strategy may be revised to improve the output as needed.

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

Strength of Evidence Key

Category 1 - The conclusions of the study are valid and strongly supported by study design, analysis, and results.

Category 2 - The conclusions of the study are likely valid, but study design does not permit certainty.

Category 3 - The conclusions of the study may be valid, but the evidence supporting the conclusions is inconclusive or equivocal.

Category 4 - The conclusions of the study may not be valid because the evidence may not be reliable given the study design or analysis.

The topic author drafts or revises the narrative text summarizing the evidence found in the literature. American College of Radiology (ACR) staff draft an evidence table based on the analysis of the selected literature. These tables rate the strength of the evidence for all articles included in the narrative text.

The expert panel reviews the narrative text, evidence table, and the supporting literature for each of the topic-variant combinations and assigns an appropriateness rating for each procedure listed in the table. Each individual panel member forms his/her own opinion based on his/her interpretation of the available evidence.

More information about the evidence table development process can be found in the ACR Appropriateness Criteria® Evidence Table Development document (see the "Availability of Companion Documents" field).

Modified Delphi Technique

The appropriateness ratings for each of the procedures included in the Appropriateness Criteria topics are determined using a modified Delphi methodology. A series of surveys are conducted to elicit each panelist's expert interpretation of the evidence, based on the available data, regarding the appropriateness of an imaging or therapeutic procedure for a specific clinical scenario. American College of Radiology (ACR) staff distributes surveys to the panelists along with the evidence table and narrative. Each panelist interprets the available evidence and rates each procedure. The surveys are completed by panelists without consulting other panelists. The ratings are a scale between 1 and 9, which is further divided into three categories: 1, 2, or 3 is defined as "usually not appropriate"; 4, 5, or 6 is defined as "may be appropriate"; and 7, 8, or 9 is defined as "usually appropriate." Each panel member assigns one rating for each procedure per survey round. The surveys are collected and the results are tabulated, de-identified and redistributed after each round. A maximum of three rounds are conducted. The modified Delphi technique enables each panelist to express individual interpretations of the evidence and his or her expert opinion without excessive bias from fellow panelists in a simple, standardized and economical process.

Consensus among the panel members must be achieved to determine the final rating for each procedure. Consensus is defined as eighty percent (80%) agreement within a rating category. The final rating is determined by the median of all the ratings once consensus has been reached. Up to three rating rounds are conducted to achieve consensus.

If consensus is not reached, the panel is convened by conference call. The strengths and weaknesses of each imaging procedure that has not reached consensus are discussed and a final rating is proposed. If the panelists on the call agree, the rating is accepted as the panel's consensus. The document is circulated to all the panelists to make the final determination. If consensus cannot be reached on the call or when the document is circulated, "No consensus" appears in the rating column and the reasons for this decision are added to the comment sections.

Not applicable

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

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

ACR Appropriateness Criteria®

Clinical Condition: Radiologic Management of Infected Fluid Collections

Variant 1: Young adult patient (20–40 years of age) presents with a 7-day history of right lower quadrant abdominal pain, fever, and leukocytosis. Physical examination shows no peritoneal signs. CT scan shows a thin-walled, 3 x 4 cm fluid collection adjacent to the cecum, nonvisualization of the appendix, and an appendicolith. Highly suspicious for appendicitis. Treatment includes antibiotics.

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

Variant 2: Elderly patient (more than 70 years of age) with a history of left hemicolectomy 2 months ago for colon carcinoma presents with abdominal pain and fever 2 weeks after placement of a 12-French drain into a complex, 5 cm abdominal fluid collection. Catheter output is 25 cc per day, and the collection is unchanged in size by CT. No fistula. Complex, purulent collection. Treatment includes antibiotics. Next step.

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

Variant 3: Young adult patient (20–40 years of age) who is an IV drug-abuser presents with fever and tachycardia and is found to have two noncommunicating splenic abscesses measuring 4 cm in diameter and accessible percutaneously through a 1 cm rim of normal splenic tissue. Appropriate management includes antibiotics.

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

Variant 4: Middle-aged patient (40–60 years of age) presents with abdominal pain radiating to the back 5 weeks after hospitalization for acute pancreatitis. Patient is afebrile. CT scan shows a 5 cm walled-off collection in the body of the pancreas indenting a broad portion of the body of the stomach. The collection is percutaneously accessible with a 3 cm window. MRCP shows a patent pancreatic duct.

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

Variant 5: Middle-aged patient (40–60 years of age) presents with a 2-week history of cough, fever, and foul-smelling sputum. Worsening despite a full course of broad-spectrum antibiotics. Sputum cultures were negative. CT scan shows a 4 cm fluid collection in the lower lobe of the right lung.

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

Variant 6: Young adult female patient (20–40 years of age) presents with abdominal pain, fever, and leukocytosis. Pelvic examination shows marked tenderness. CT scan shows a 4 cm walled-off probable tubo-ovarian abscess (TOA), safely accessible from the transgluteal, transvaginal, and transrectal approaches. Appropriate first-line treatment includes antibiotics.

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

Summary of Literature Review

Diagnosis and Treatment of Fluid Collections

Detection and evaluation of fluid collections are typically accomplished with computed tomography (CT) and/or ultrasound (US) in patients who manifest signs and symptoms of possible infection or clinical impairment. Routine imaging of postoperative patients should be discouraged, as postoperative fluid collections are commonly present and may not be infected. Expense and availability limit magnetic resonance imaging (MRI) for this purpose. US is fast, avoids ionizing radiation, and provides more detailed evaluation of the internal structure and composition of complex collections. US is more limited in the evaluation of collections deep within the soft tissues or adjacent to loops of bowel than CT or MRI, and it fails to penetrate intracavitary, pulmonary, or enteric gas. Therefore, US is more commonly used to screen for superficial or large fluid collections and collections within or adjacent to solid organs. CT provides the advantage of detection of deep collections and the use of intravenous (IV) and oral contrast to distinguish collections from adjacent vasculature or bowel. CT is usually the first-line modality in patients with fever of unknown origin. Multidetector CT scanners with sagittal and coronal reformatting can help distinguish collections from adjacent structures.

The choice of imaging guidance for draining fluid collections varies with availability, operator expertise, body habitus, presence of adjacent structures, size and location of the collection, and presence of intracavitary or enteric gas. The choice of treatment options for a given collection may vary among operators and depends on size, location, and clinical presentation. Options include antibiotics coupled with supportive measures such as bowel rest and hyperalimentation, needle aspiration for drainage or to hone antibiotic coverage, percutaneous catheter drainage (PCD), PCD with sclerotherapy, PCD with thrombolytic therapy, endoscopic drainage, immediate surgery, or delayed surgery.

Two basic techniques are available for PCD: Seldinger and trocar. For percutaneous aspiration and drainage, success thresholds of 95% and 85% have been recommended. Choice of technique is primarily operator dependent, though the trocar technique has been advocated for endocavitary drain placement to avoid the risk of loss of access during the process of serial dilation — a complication associated with the Seldinger technique.

Fluid Collections in the Abdomen

Abdominal abscesses are most often the result of diverticulitis, appendicitis, Crohn's disease, and recent laparotomy. When possible, open surgical drainage (OSD) is avoided due to a high rate of morbidity and mortality. For the management of small (<3 cm) collections, most authors advocate a trial of antibiotics alone with consideration given to needle aspiration to hone antibiotic coverage for persistent cases. This approach uses follow-up imaging and repeat aspiration if the collection does not resolve. PCD is advocated for larger collections. Peritoneal signs, active hemorrhage, and lack of maturation of the abscess wall have been suggested as contraindications to PCD. The highest success rates have been achieved for abscesses resulting from recent laparotomy, and as a result, PCD with antibiotics is usually the only required treatment for this entity.

For mature abscesses associated with Crohn's disease, an initial combination of PCD, antibiotics, high-dose steroids, bowel rest, and (on occasion) hyperalimentation has been advocated to reduce the failure rate of PCD, temper the acute infection, and allow for surgical resection under more sterile, elective conditions. Some patients (33%–50%) will ultimately require surgical drainage or resection, but most authors still advocate a first-line trial of PCD if technically possible. In a study of 25 patients with Crohn's disease, PCD performed an average of 37 days before surgery significantly reduced the rate of severe, postoperative septic complications such as anastomotic leak, intraabdominal abscess, and fistula.

For mature abscesses associated with appendicitis, an initial combination of PCD, antibiotics, bowel rest, and (on occasion) hyperalimentation has been advocated for the same reason. Some disagreement exists in the literature regarding the need for subsequent ("interval") appendectomy after successful PCD. In a study of 1,012 patients with appendicitis, investigators evaluated the need for PCD and the subsequent need for interval appendectomy after successful PCD. On initial presentation, the vast majority of patients with appendicitis required emergent surgery. If nonoperative management was successful, 80% of patients were cured without surgery. The push for conservative management, including PCD, rather than acute appendectomy for patients with appendicitis complicated by abscess or phlegmon is supported by a meta-analysis of 1,572 patients in 17 studies showing significant reductions in complication rates.

Fluid Collections in the Pelvis

Depending on location, pelvic fluid collections can be drained via the transabdominal, transgluteal, transrectal, transvaginal, and transperineal routes. The efficacy and safety of these routes have been established by a number of retrospective reports. The choice of route for a given abscess varies among operators and institution type, with transrectal and transvaginal approaches used much more commonly in academic centers. In general, reports have advocated the use of the most sterile route possible when aspirating or draining a potentially sterile collection. Using this rationale, the transabdominal and transgluteal routes would be preferable to the endocavitary routes for a potentially sterile collection. The transperineal route is most commonly used in patients after low anterior resection for rectal cancer. Some disagreement exists in the literature regarding the level and incidence of significant or persistent pain when comparing the transgluteal and endocavitary routes. At a minimum, conscious sedation is required for these procedures. The route of transgluteal drainage through the greater sciatic foramen should be medial to the sciatic nerves and below the level of the piriformis muscle to prevent the complications of persistent pain or injury to the gluteal arteries.

For tubo-ovarian abscesses, some disagreement exists in the literature regarding the appropriate treatment. Many resolve with antibiotics and supportive care, but more recently, early aspiration (for simple collections) and transvaginal or laparoscopic drainage (for complex collections) have been advocated to prevent prolongation of the disease and the potential associated loss of fertility. A literature review showed that, for women of reproductive age desiring pregnancy, if tubo-ovarian abscess exists without intra-abdominal rupture, medical management and laparoscopic drainage within 24 hours results in pregnancy rates ranging from 32% to 63% compared to 4% to 15% with medical management alone. The route and method of drainage depend on operator and patient preference as well as individual anatomic considerations.

For prostatic abscesses, the longstanding treatment method has been transurethral drainage, but recent small studies have demonstrated that guidance of needle aspiration or placement of small-bore pigtail catheters using transrectal US can shorten hospital stay and provide a viable alternative.

Fluid Collections of the Solid Organs

Hepatic abscesses may be treated differently depending on their size and etiology. Pyogenic abscesses most often result from portal venous seeding of diverticulitis and appendicitis, but they also may occur from obstruction of the biliary system, including the gallbladder. Pyogenic abscesses complicate 1.4% of hepatic artery embolization (HAE) procedures. Morbidity and mortality from pyogenic abscess may be increased in patients undergoing HAE who have a history of bilioenteric anastomosis or an incompetent sphincter of Oddi. For pyogenic abscesses under 3 cm in diameter, authors have advocated using antibiotics, either alone or in conjunction with needle aspiration, with excellent success rates. For pyogenic abscesses over 4 to 5 cm in diameter, PCD is often required. Amebic abscesses have been shown to respond extremely well to antibiotics without intervention, regardless of size, but occasionally they require needle aspiration.

Splenic abscesses were considered to be surgical cases as recently as the 1990s, but a number of small, retrospective series have readdressed this issue, some advocating the benefits of PCD for solitary, simple collections and splenectomy for multiple collections. In a retrospective study of 18 children with splenic abscesses, IV antibiotics were administered to all patients, and 10 underwent PCD for the inclusionary threshold of an abscess diameter >3 cm. Clinical response was 100%. Preservation of splenic function is maintained by the use of PCD techniques, and this should be attempted where possible and safe. Current data are relatively sparse, and some disagreement exists.

A significant amount of confusing terminology is used when discussing pancreatitis, including acute and subacute fluid collections. Operators are urged to adhere to standards such as the Atlanta criteria when describing such collections. Pancreatic pseudocysts may resolve spontaneously if they are small, stable, and sterile. Drainage is generally advocated for large (≥5 cm), rapidly enlarging, painful, obstructing, or infected pseudocysts. Techniques for drainage are multidisciplinary, and continued disagreement on the optimal use of these techniques leads to a variety of treatment algorithms for these patients. Treatment options include endoscopic drainage with or without creation of a cystenterostomy, surgical drainage with or without creation of a cystenterostomy, and PCD. PCD generally requires a prolonged period of drainage in these patients compared to abscesses in other locations, but high rates of eventual success have been reported. Complete occlusion of the main pancreatic duct central to the pseudocyst may lead to failure of PCD and necessitate use of surgical or endoscopic marsupialization to bowel.

Pancreatic abscesses are associated with a high rate of mortality and are drained emergently. For suboptimal surgical candidates, minimally invasive alternatives include endoscopic drainage or PCD. PCD is typically used as a temporizing measure prior to surgery since cure rates range from 14% to 32%. High rates of clinical success have been reported using endoscopic techniques, which may be optimal for more central collections and those abutting the greater curvature of the stomach. Large, complex collections involving the tail of the pancreas or not in direct communication with the pancreas may be better treated by PCD.

Renal abscesses may be cured by medical treatment in over half of cases, even up to 64%, and both renal and perirenal abscesses may otherwise require PCD, surgical drainage, or nephrectomy.

Fluid Collections in the Chest

Parenchymal lung abscesses most often occur from aspiration of anaerobic oropharyngeal bacteria or from fungal organisms. Alcoholics, immune-compromised patients, and patients with bronchial obstruction are predisposed. The organism is usually determined by culture of sputum or blood and, less optimally, by culture of cavitary fluid obtained by needle aspiration or bronchoscopy. The majority (typically >80%) are treated to resolution with antibiotics and conservative management. PCD and surgical resection/drainage are generally reserved for cases that persist or worsen despite antibiotics. Empyemas are typically drained by PCD if they are focal or uniloculated, and by surgical chest tube placement if they are multiple, multiloculated, complex, and extensive. Persistent, complex collections and organizing hemothoraces have been successfully treated with instillation of fibrinolytic agents. Communication to the bronchial tree in the form of a bronchopleural fistula may require prolonged catheter drainage with the catheter placed to suction water seal.

Persistent, large, malignant, and benign pleural effusions have been successfully treated or managed with pleurodesis through small-bore catheters or permanent drainage catheters with one-way valves to prevent pneumothorax.

Mediastinal abscesses are most commonly the result of thoracic surgical procedures, and usually require PCD. Though these cases may be technically challenging, limited studies show low complication rates, technical success approaching or reaching 100%, and clinical success exceeding 90% without the need for surgery.

Fluid Collections Refractory to Percutaneous Catheter Drainage

Persistence of fluid collections despite PCD may be the result of factors such as complex loculations and septations; fistulization of the cavity to the enteric, biliary, genitourinary, pancreatic, or bronchial systems; the presence of neoplastic tissue; and communication of the cavity to the lymphatic system. Depending on the reason for incomplete drainage, options may include catheter manipulation, catheter upsizing, diversion of upstream obstructions, or surgical drainage — both open and laparoscopic. Fibrinolysis of complex, multiseptated fluid collections refractory to PCD by intracavitary instillation of fibrinolytic agents such as tissue plasminogen activator has been reported.

Available reports are limited in number and often small, but high rates of clinical success have been demonstrated retrospectively for abdominal and pelvic abscesses as well as organizing hemothorax and empyema. Case reports have even demonstrated success in the fibrinolytic treatment of refractory, complex splenic abscesses. In a prospective study of 100 patients with abdominal abscesses randomized to regular instillation of sterile saline versus urokinase during catheter drainage, the urokinase group had no increase in complication rate but showed a reduction in hospital stay, drainage duration, and overall cost of treatment. In a similar though smaller prospective, randomized study of 20 patients with complicated intra-abdominal abscesses, patients receiving intracavitary alteplase showed a 72% clinical success rate compared to 22% for patients receiving sterile saline. Rates of bleeding complications using intracavitary recombinant tissue plasminogen activator (r-tPA) have been low to zero for pelvic, abdominal, and chest collections, except for a 33% rate of pleural hemorrhage noted for intrapleural r-tPA for patients on anticoagulation.

For persistent sterile collections such as cysts, lymphoceles, and seromas, a number of reports describe high rates of success in shortening the period of catheterization by intracavitary instillation of sclerotherapy agents such as ethanol or tetradecyl sulfate. For cases of fistulization of the abscess cavity to enteric, biliary, genitourinary, pancreatic, or bronchial systems, PCD may be successful with prolonged catheterization.

PCD of an infected or fluid-filled tumor may be inadvertent or intentional. For good surgical candidates, tumor resection is typically performed. For poor surgical candidates, the period of catheterization may be markedly prolonged or indefinite. Despite this finding, patients with infected, inoperable tumors at risk for systemic infection may opt for PCD.

On occasion, PCD fails to resolve the associated fluid collection despite these measures. In such circumstances, the benefit of PCD may be to limit the hematogenous or local spread of infection and improve the acute clinical presentation, thereby preparing the patient for a more elective, single-step surgical procedure. This treatment algorithm has been described for appendicitis and Crohn's disease.

Summary

• CT and US are the most common modalities used to diagnose and guide PCD of fluid collections. US provides more detailed evaluation of complex collections and excellent evaluation of the solid organs, but is more limited in the evaluation of collections deep within the soft tissues, adjacent to loops of bowel, or behind or containing gas. CT provides better detection of deep collections, distinction from adjacent vasculature or bowel, and more complete evaluation of patients with fever of unknown origin.
• Abdominal abscesses are typically drained with PCD if they are large (>4–5 cm), mature, and not associated with peritonitis or active hemorrhage. Imaging immediately after drainage will allow determination if additional catheters are necessary, as all collections should be preferably drained at the initial setting unless lack of a safe pathway precludes such an approach.
• Pelvic collections may be drained using multiple routes of access, including transabdominal, transgluteal, transperineal, and endocavitary. Sterile routes are more appropriate for potentially sterile collections.
• Collections may be refractory to PCD in cases of fistula formation, complex internal structure, the presence of neoplastic tissue, or communication to the lymphatic system. Depending on the cause, treatment options include prolonged catheterization, catheter manipulation or upsizing, diversion of upstream obstruction, bowel rest, instillation of fibrinolytic agents, instillation of sclerotherapy agents, and surgical drainage.
• PCD has been applied to splenic and pancreatic abscesses with variable results and recommendations in the literature, suggesting that the best current approach is multidisciplinary, depending on the extent and location of disease.
• Smaller abscesses and abscesses of the kidney and lung parenchyma have a high rate of clinical response to antibiotic therapy and supportive care, with more invasive treatments typically reserved for extensive or refractory cases.

Abbreviations

• CT, computed tomography
• IV, intravenous
• MRCP, magnetic resonance cholangiopancreatography
• PCD, percutaneous catheter drainage
• TOAs, tubo-ovarian abscesses
• vs, versus

Algorithms were not developed from criteria guidelines.

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

Appropriate use of percutaneous catheter drainage (PCD) and other interventions for the treatment and management of infected fluid collections

Peritoneal signs, active hemorrhage, and lack of maturation of the abscess wall have been suggested as contraindications to percutaneous catheter drainage (PCD).

The 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 examinations 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.

An implementation strategy was not provided.

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

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

Committee on Appropriateness Criteria, Expert Panel on Interventional Radiology

Panel Members: Jonathan M. Lorenz, MD (Principal Author and Panel Vice-chair); Charles E. Ray, Jr, MD, PhD (Panel Chair); Charles T. Burke, MD; Michael D. Darcy, MD; Nicholas Fidelman, MD; Frederick L. Greene, MD; Eric J. Hohenwalter, MD; Thomas B. Kinney, MD; Kenneth J. Kolbeck, MD; Jon K. Kostelic, MD; Brian E. Kouri, MD; Ajit V. Nair, MD; Charles A. Owens, MD; Paul J. Rochon, MD; Don C. Rockey, MD; George Vatakencherry, MD

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Lorenz JM, Funaki BS, Ray CE Jr, Brown DB, Gemery JM, Greene FL, Kinney TB, Kostelic JK, Millward SF, Nemcek AA Jr, Owens CA, Reinhart RD, Rockey DC, Silberzweig JE, Vatakencherry G, Expert Panel on Interventional Radiology. ACR Appropriateness Criteria® percutaneous catheter drainage of infected fluid collections. [online publication]. Reston (VA): American College of Radiology (ACR); 2009. 8 p.

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

Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site.

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

The following are available:

• ACR Appropriateness Criteria®. Overview. 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.
• ACR Appropriateness Criteria®. Literature search process. Reston (VA): American College of Radiology; 1 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Evidence table development. Reston (VA): American College of Radiology; 4 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.

None available

This NGC summary was completed on May 13, 2010. This NGC summary was updated by ECRI Institute on February 22, 2012.

Instructions for downloading, use, and reproduction of the American College of Radiology (ACR) Appropriateness Criteria® may be found on the ACR Web site .