Pyogenic liver abscess CT

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Yamuna Kondapally, M.B.B.S[2]

CT scan findings of pyogenic liver abscess include peripherally enhancing and centrally hypo attenuating lesions, solid or gas in the lesions (gas in the form of bubbles or air fluid levels), segmental, wedge-shaped or circumferential perfusion abnormalities, early enhancement may be seen on contrast enhanced CT scans, the double target sign and cluster sign (shown below).^[1][2][3][4]

CT scan findings of pyogenic liver abscess include:^[1][2][3][4]

• Peripherally enhancing and centrally hypo attenuating lesions
• Solid or gas in the lesions (gas in the form of bubbles or air fluid levels)
• Segmental, wedge-shaped or circumferential perfusion abnormalities, with early enhancement, may be seen
• On contrast enhanced CT scans, the double target sign is a characteristic imaging feature of liver abscess
• Double target sign:

• Central low attenuation lesion (fluid filled) is surrounded by a high attenuation inner rim and a low attenuation outer ring
• The inner ring (abscess membrane) indicates early contrast enhancement which persists on delayed images, in contrast to the outer rim (edema of the liver parenchyma) which only enhances on delayed phase

• Cluster sign (shown below):

• Feature of pyogenic liver abscess
• Aggregation of multiple low attenuation liver lesions in a localized area to form a solitary larger abscess cavity