Sonographic findings in hepatic amebic abscess

Sonograms of 143 hepatic amebic abscesses in 106 patients were analyzed retrospectively. A strongly suggestive but not pathognomonic pattern was noted in 54 abscesses (37.8%), consisting of (a) lack of significant wall echoes, (b) a round or oval configuration, (c) less echogenicity than the normal parenchyma, with fine, homogeneous low-level echoes throughout at high gain, (d) a location contiguous to the liver capsule, and (e) distal sonic enhancement. Most other hepatic abscesses (53.1%) had all but one or two of these features. Thirteen patients (9%) had bizarre sonographic findings. Peripheral or central areas of increased echogenicity occurred more frequently than previously reported. At normal gain settings, most lesions (53.8%) were predominantly anechoic. The above pattern and trans-diaphragmatic pleural involvement were helpful in the diagnosis.