Amebic liver abscess: MR imaging.

Hepatic magnetic resonance (MR) imaging was performed in 12 patients with 13 amebic liver abscesses. While no specific image or intensity pattern was noted, most lesions were round or oval with smooth, well-defined margins; had decreased signal intensity compared with that of liver parenchyma on T1-weighted images and increased signal intensity on T2-weighted images; and had prominent, often multiple rims of variable signal intensity. Signal homogeneity within the abscess was present more often on T1- than on T2-weighted images. Diaphragmatic disruption was seen in two cases on coronal MR images. An amebic empyema was differentiable from sympathetic pleural effusions by its hyperintensity on both T1- and T2-weighted images. In patients who also underwent computed tomography (CT) or ultrasonography (US), no lesion was missed with any modality, and except for shape, no consistent features were found among images obtained with the different modalities. The data suggest that CT, US, and MR imaging are comparably effective in the detection of amebic abscess.