Tc-99m-IDA gallbladder kinetics and response to CCK in chronic cholecystitis

The cholecystographic pattern and the contractile response of the gallbladder (GB) to cholecystokinin (CCK) were studied in 101 consecutive patients with uncomplicated chronic cholecystitis confirmed by pathology. Sequential GB images were obtained after administration of 5 mCi ^99mTc-Disofenin and the ejection fraction was determined following a 15 min infusion of CCK. Sixteen of 101 (16%) GB failed to visualize upto 4 h; of the remaining patients, 3/85 (4%) showed delayed visualization beyond 1 h, and 82/85 visualized within 1 h. The mean ejection fraction (EF) in 67 patients was 56.9%±27.5% compared to 74.8%±19.8% in a normal control group of 27 subjects (P0.005). However, there was a large overlap as 76% of chronic cholecystitis patients had EF values falling within the full normal range. GB disease could be identified with confidence when the EF was less than 35%, i.e. below the 2 standard deviation range of normal. On the basis of radionuclide kinetic studies alone, the majority of patients with chronic cholecystitis cannot be distinguished from normal.