Low mechanical index contrast-enhanced sonographic findings of pyogenic hepatic abscesses

Low mechanical index contrast-specific sonography is a new technique that uses the harmonic capabilities of second-generation contrast agents to produce real-time contrast-enhanced gray-scale images. We describe the contrast-specific sonographic findings of pyogenic hepatic abscesses.

Contrast-specific sonography was used to assess eight cases of aspiration-confirmed pyogenic liver abscesses. All cases were correlated with multiphasic helical CT findings. Continuous sonographic exploration allowed recognition of morphologic details not detectable on CT images. Contrast-specific sonograms showed features including rim enhancement, arteries along abscess margins and internal septa, dense and persistent septal enhancement, absent microcirculation in fluid and necrotic components, transient arterial phase hypervascularity around abscesses, and portal phase hypovascularity around abscesses. This constellation of findings is suggestive of liver abscess.