Is an Unenhanced CT Scan of the Abdomen and Pelvis Accurate in Diagnosing Acute Appendicitis in Adults?

With the advent of more sophisticated CT scanners, imaging without contrast (unenhanced) is increasingly utilized in the evaluation of adults with suspected
acute appendicitis. Oral contrast presents a significant delay to imaging. Intravenous contrast presents the small, but real risks of allergic reaction and
contrast nephropathy. There is sufficient literature to support the use of unenhanced CT of the abdomen and pelvis (CT AP) to evaluate adults for acute
appendicitis.

There are no large, prospective, randomized studies directly comparing the diagnostic accuracy of CT AP with contrast and unenhanced CT in the setting of acute appendicitis. However there are separate studies that address the accuracy of CT AP with IV and/or oral contrast or unenhanced CT AP, separately.

References and Literature Grading (PDF)