HIDA scan in a patient with acute cholecystitis

The hepatic iminodiacetic acid (HIDA) scan is abnormal and shows absence of filling of the gallbladder, indicating obstruction of the cystic duct. The duodenum starts to fill with radioisotope at about 20 minutes (white arrow). The radioisotope flows directly into the duodenum (white arrow) starting at 20 minutes. The gallbladder never fills during the course of the 60 minute examination. These findings are consistent with the diagnosis of acute cholecystitis.