CT and MRI findings of acute cholecystitis
CT and MRI findings include smooth or irregular gallbladder wall thickening, generally ≥ 4 mm in thickness (sometimes with decreased attenuation/high T2-weighted signal intensity because of edema); gallbladder distention (>5 cm in width); pericholecystic inflammatory fat stranding or fluid; gallstones or gallbladder sludge; increased gallbladder wall enhancement; and transiently increased late arterial phase enhancement of the adjacent liver parenchyma owing to the inflammatory process ( Figure 32-5 ). Both CT and MRI have high sensitivity and specificity for the diagnosis of acute cholecystitis. Note that only ≈75% of gallstones are detected on CT, whereas >95% are visualized on MRI.
