Hepatic pseudolesion: appearance of focal low attenuation in the medial segment of the left lobe at CT arterial portography.

Fifty computed tomographic (CT) arterial portography (CTAP) examinations were retrospectively reviewed to determine the prevalence of a pseudolesion, defined as a focal low-attenuation area located in the medial segment of the left hepatic lobe immediately anterior to the porta hepatis. This pseudolesion was considered to be present if the described low-attenuation area was detected with CTAP but was not confirmed with one or more of the following: delayed-iodine hepatic CT (DICT), magnetic resonance (MR) imaging, surgery, and routine follow-up abdominal CT. A pseudolesion was suspected in seven of 50 (14%) cases. Correlation was made with findings at DICT in all seven cases and at MR imaging in five of the seven cases. In addition, correlation with findings at pathologic examination was made in four of the seven cases (57%). Correlation with findings on one or more follow-up abdominal CT scans was also made in three of the seven cases.