SPECT/CT unequivocally depicts dilated cystic duct sign on hepatobiliary scintigraphy in acute cholecystitis.

The dilated cystic duct sign (DCDS) on hepatobiliary scintigraphy can lead to a false-negative test in patients with acute cholecystitis. Presented is a case of acute gangrenous cholecystitis with probable DCDS on the planar study that was unequivocally delineated on SPECT/CT imaging. SPECT/CT may be useful when planar findings suggest DCDS.