Unenhanced CT for the Diagnosis of Minimal-Fat Renal Angiomyolipoma

Abstract

Coexisting classic angiomyolipomas and the absence of calcification are associated with minimal-fat angiomyolipomas; by contrast, the hypodense rim sign is not useful for diagnosis. Minimal-fat angiomyolipomas have increased absolute and relative (normalized to renal parenchyma) density compared with RCC; however, overlap in density values limit diagnostic utility.