Case 366:   Abscess (amebic)

Diagnostic Category:

Clinical Presentation:

41 year old man returning from a long journey around the world with right epigastric pain and fever.

US: Large, with typical "double-rim sign" on CEUS

Imaging Findings:

Gray-scale ultrasound demonstrates round well-defined mass with heterogeneous debris and no posterior acoustic enhancement; absent color Doppler flow.

Contrast enhanced ultrasound shows an inner thin hypervascular capsule in the arterial phase, a barely perceptible outer thin rim of edema and compressed parenchyma ("double-rim sign"), surrounded by homogeneously hypervascular hepatic parenchyma.  Compare hepatic enhancement to renal enhancement (bottom right) on the arterial phases to appreciate hypervascularity of liver parenchyma, caused by inflammation.  

Courtesy Dr. Gerd Stuckmann, Institute for Radiology and Nuclear Medicine, Kantonsspital Winterthur,  Switzerland.