Independent Predictors of Acute Appendicitis on CT with Pathologic Correlation

Appendix diameter is the best single diagnostic criterion for appendicitis on CT scan. A cutoff between 8 and 9 mm provided the best balance of sensitivity/specificity in our study population, whereas a cutoff between 6 and 7 mm improved sensitivity at the expense of specificity. The presence of appendiceal enhancement provided additional diagnostic information, but other secondary signs of appendicitis did not improve diagnostic accuracy.