Gallbladder carcinoma and chronic cholecystitis: differentiation with two-phase spiral CT.

The objective of the present study was to determine whether an analysis of two-phase spiral computed tomographic (CT) features provides a sound basis for the differential diagnosis between gallbladder carcinoma and chronic cholecystitis. Eighty-two patients, 35 with gallbladder carcinoma and 47 with chronic cholecystitis, underwent two-phase spiral CT. We reviewed the two-phase spiral CT features of thickness and enhancement pattern of the gallbladder wall seen during the arterial and venous phases. Mean wall thicknesses were 12.6 mm in the gallbladder carcinoma group and 6.9 mm in the chronic cholecystitis group. The common enhancement patterns seen in gallbladder carcinoma were (a) a highly enhanced thick inner wall layer during the arterial phase that showed isoattenuation with the adjacent hepatic parenchyma during the venous phase (16 of 35, 45.7%) and (b) a highly enhanced thick inner wall layer during both phases (eight of 35, 22.9%). The most common enhancement pattern of chronic cholecystitis was isoattenuation of the thin inner wall layer during both phases (42 of 47, 89.4%). In conclusion, awareness of the wall thickening and enhancement patterns in gallbladder carcinoma and chronic cholecystitis on two-phase spiral CT appears to be valuable in differentiating these two different disease entities.