MR imaging of pathologic abdominal fluid collections.

A retrospective comparison was made of the capability of magnetic resonance (MR) imaging and CT to display and characterize pathologic abdominal fluid collections. Fluid collections in 41 patients were analyzed: ascites (seven patients), hematoma (five), pancreatic pseudocyst (four), biloma (two), abscess (four), simple renal cyst (nine), hemorrhagic renal cyst (two), hydronephrosis (four), hemonephrosis (two), and cystic metastases (two). Most fluid collections were equally demonstrated by the two modalities. Walls around fluid collections were better demonstrated CT. Six fluid collections appeared heterogeneous on MR but were homogeneous or nearly so on CT.