Portal Venous Gas Secondary to Gangrenous Gallbladder and Mirizzi Syndrome Diagnosed by Gray-Scale Sonography but Not on 64-Slice MDCT: A Case Report and Literature Review

Portal venous gas is a rare entity that is associated with many fatal and nonfatal conditions. Its exact etiology remains unclear. Computed tomography (CT) has been described as a sensitive and primary imaging tool for detecting this condition, but there are only a few case reports in the literature where portal venous gas was not detected on CT scan but was found by sonography. This case reports portal venous gas developing secondary to gangrenous gallbladder with Mirizzi syndrome which was diagnosed by sonography but remained undetected on 64-slice MDCT.