How do I know which radiologic tests to choose when evaluating abdominal pain? — Dorothy Malone Rising, ANP, CDE, Johnson, Vt.

Contrast is required whenever there is a differential of cancer. If a patient presents with acute abdominal pain consistent with appendicitis, diverticulitis, or the like, contrast is not necessary; inflammation will be evident on a plain CT. Another consideration for use of contrast includes the renal function of the patient, which is particularly important to assess prior to contrast administration for older patients.

If you are concerned about any abnormality in the lower half of the abdomen, abdomen/pelvis CT is necessary, because anatomical regions overlap. If the concern is cholecystitis, perforated gastric ulcer, or anything else in the epigastric region, a full abdominal CT is recommended.—Rebecca H. Bryan, APRN, CNP (155-13)