Presentation
Right upper quadrant pain and fever.
Patient Data
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A 65×50 mm thick walled multiloculated lesion (cluster sign) is present at the right hepatic lobe, with central low attenuation fluid-filled component surrounded by a high attenuation inner rim and a low attenuation outer ring (double target sign). Additionally, perilesional parenchymal hyperenhancement is also evident in the early phase.
Case Discussion
Regarding patient history, features on CT images are typical for pyogenic hepatic abscesses.
The cluster sign refers to an aggregation of multiple low attenuation liver lesions in a localized area to form a solitary larger abscess cavity suggesting pyogenic hepatic abscesses.1
The double target sign is also a characteristic imaging feature of hepatic abscess where the abscess membrane demonstrates early contrast enhancement, in contrast to the outer rim, which only enhances the delayed phase due to the edema of the liver parenchyma.2