Multidetector computed tomography diagnosis of primary and secondary epiploic appendagitis

Purpose  The aim of this study was to evaluate the epiploic appendages in patients with acute abdomen using multidetector computed tomography (MDCT) and to determine the incidence of primary and secondary epiploic appendagitis (EA). Materials and methods  A radiologist reviewed MDCT images from 1338 patients with acute abdomen for visible epiploic appendages. Two radiologists then reviewed the MDCT images showing inflamed epiploic appendages and diagnosed primary EA, secondary EA, or other conditions by consensus. The CT criteria for primary EA are a round or oval pericolonic fatty lesion with a hyperattenuated rim and adjacent fat stranding, without other causes of inflammation. Secondary EA is diagnosed if an epiploic appendage is found to be due to inflammation from other inflammatory entities. Results  Epiploic appendages were identified in 19 patients. Four patients (0.3%) had a retrospective CT diagnosis of primary EA. Twelve patients (0.9%) had a retrospective CT diagnosis of secondary EA (primary condition was diverticulitis in 10 patients and inflammatory bowel disease in 2 patients). The remaining three patients had calcification of an epiploic appendage suggestive of old EA. Conclusion  Primary EA should be included in the differential diagnosis of acute abdomen. Occasionally, inflammation of the epiploic appendages is secondary to other inflammatory conditions.