Anorectal Disease

Variant: 1   Suspected perianal disease. Abscess or fistula. Initial imaging.
Procedure Appropriateness Category
MRI pelvis without and with IV contrast Usually Appropriate
CT pelvis with IV contrast Usually Appropriate
US endoanal May Be Appropriate
MRI pelvis without IV contrast May Be Appropriate
CT pelvis without IV contrast May Be Appropriate
Radiography pelvis Usually Not Appropriate
Fluoroscopy contrast enema Usually Not Appropriate
Fluoroscopy fistulography anus Usually Not Appropriate
CT pelvis without and with IV contrast Usually Not Appropriate
Variant: 2   Suspected rectal fistula. Rectovesicular or rectovaginal. Initial imaging.
Procedure Appropriateness Category
MRI pelvis without and with IV contrast Usually Appropriate
CT pelvis with IV contrast Usually Appropriate
US pelvis transrectal May Be Appropriate
Fluoroscopy contrast enema May Be Appropriate
Fluoroscopy cystography May Be Appropriate
Fluoroscopy vaginography May Be Appropriate
MRI pelvis without IV contrast May Be Appropriate
Radiography pelvis Usually Not Appropriate
CT pelvis without IV contrast Usually Not Appropriate
CT pelvis without and with IV contrast Usually Not Appropriate
Variant: 3   Suspected proctitis or pouchitis. Initial imaging.
Procedure Appropriateness Category
MR enterography Usually Appropriate
MRI pelvis without and with IV contrast Usually Appropriate
CT pelvis with IV contrast Usually Appropriate
CT enterography Usually Appropriate
Fluoroscopy contrast enema May Be Appropriate
MRI pelvis without IV contrast May Be Appropriate
US pelvis Usually Not Appropriate
Radiography pelvis Usually Not Appropriate
CT pelvis without IV contrast Usually Not Appropriate
CT pelvis without and with IV contrast Usually Not Appropriate
FDG-PET/CT skull base to mid-thigh Usually Not Appropriate
WBC scan abdomen and pelvis Usually Not Appropriate
Variant: 4   Suspected complication postproctectomy or coloproctectomy or colectomy with pouch or other anastomosis. Initial imaging.
Procedure Appropriateness Category
MRI pelvis without and with IV contrast Usually Appropriate
CT abdomen and pelvis with IV contrast Usually Appropriate
CT pelvis with IV contrast Usually Appropriate
Fluoroscopy contrast enema May Be Appropriate
MRI pelvis without IV contrast May Be Appropriate
CT abdomen and pelvis without IV contrast May Be Appropriate
CT pelvis without IV contrast May Be Appropriate
US pelvis transrectal Usually Not Appropriate
Radiography abdomen and pelvis Usually Not Appropriate
CT abdomen and pelvis without and with IV contrast Usually Not Appropriate
CT pelvis without and with IV contrast Usually Not Appropriate

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please visit https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

Appropriateness Category Name

Appropriateness Rating

Appropriateness Category Definition

Usually Appropriate

7, 8, or 9

The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.

May Be Appropriate

4, 5, or 6

The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.

May Be Appropriate (Disagreement)

5

The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.

Usually Not Appropriate

1, 2, or 3

The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.


































































The 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 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