Imaging – CT

CT has a greater overall accuracy of 94% (sensitivity 94%, specificity 95%) in diagnosing appendicitis compared to USS [12-14]. However, CT is costly, may not be readily available and can result in significant radiation exposure to patients. Studies that have shown improved accuracy of CT over USS predominantly utilised helical CT without contrast [13]. Similarly to USS, CT can rule in but not rule out appendicitis. CT may be better at identifying other pathologies than USS.

If a patient is felt to have a high likelihood of appendicitis then unnecessary imaging should not delay theatre. Remember the mortality and morbidity in appendicitis is higher if the appendix perforates.

Learning bite

Helical CT without contrast is the investigation of choice in patients in whom there are equivocal findings or the diagnosis is not clear.