Multislice CT refines acute appendicitis diagnosis

Radiologists are taking advantage of new data that support imaging techniques to rule out acute appendicitis. They may help lead to consensus on the best protocols to diagnose this condition accurately, according to studies presented Monday.

In a study by Dr. S. Ganguli and colleagues at Harvard University, researchers sought to determine the negative predictive value of the nonvisualized appendix on multislice CT of symptomatic patients. They retrospectively reviewed 394 consecutive patients presenting with signs and symptoms of acute appendicitis to the emergency room between May and October of 2003.

The investigators found they could safely rule out acute appendicitis in patients with right lower quadrant pain and a nonvisible appendix on multislice CT. The Harvard data validate previous findings published by Northwestern University physicians in the American Journal of Roentgenology.

Only 79 of the Harvard patients had acute appendicitis, while 78 showed a different cause for lower abdominal pain on CT. A normal appendix was visualized in 178 patients. The investigators determined the negative predictive value of a nonvisualized appendix for acute appendicitis was 98.3%.

In another study, Boston researchers proposed a multimodality approach. They enrolled 500 consecutive patients and classified them according to their preoperative condition, symptoms, and imaging needs:

• 135 young male patients underwent no imaging

• 70 women of reproductive age underwent ultrasound

• 15 pregnant women underwent MR imaging

• 280 patients not fitting the above categories underwent CT

The diagnostic algorithm was highly accurate and minimized time, costs, and radiation burden.

Some attendees, however, expressed their concern about sending HIV patients with appendicitis-mimicking symptoms directly into the operating room without the proper preoperative examination.

For more information from the online Diagnostic Imaging archives:

CT safely rules out acute appendicitis

FDA okays radiolabeled agent to image appendicitis

Spiral CT proves superior for diagnosing appendicitis