Dr. Darren Lu and Dr. Hisham Tchelepi conducted a retrospective review of 158 women ages 14 to 45 who presented with pain suspicious for appendicitis. All of the women had an initial right lower-quadrant ultrasound; some had subsequent CT scans if indicated.
Ultrasound confirmed a normal appendix in 23 cases (14.6%), although two of these patients had follow-up CT, which also showed a normal appendix. Twenty-seven patients (17.1%) showed an appendix consistent with acute appendicitis; eight of these (29.6%) had follow-up CT, seven of which confirmed acute appendicitis.
Also, 108 cases were nondiagnostic on ultrasound. None of these patients were subsequently diagnosed with acute appendicitis on CT or clinically, according to Lu and Tchelepi.
Ultrasound had a positive predictive value of 95.8% and a negative predictive value of 100% when the appendix was identified, similar to previously reported data for CT, the researchers wrote. This suggests the technology could be a good alternative for reducing radiation exposure for this population, Lu and Tchelepi concluded.
