Introduction: Despite presence of a body of evidence in support of high accuracy of cholecystokinin cholescintigraphy (CCK-CS) , for diagnosis of chronic cholecystitis(CC) , some authors have claimed that  gallbladder ejection fraction (GBEF)  has poor predictive diagnostic values. The purpose of this study was to determine if there is any difference in GBEF between normal individuals and patients with CC.
Methods: In a prospective case-control study, we studied 36 subjects as control group who did not have any abdominal symptoms, or history of abdominal disease or gallstone. Patients group were 42 with established choronic calcalous cholecystitis(CCC)  who complaining of chronic biliary-like pain and had gallstone on ultrasonography.  All subjects underwent gallbladder scintigraphy and GBEF was calculated at 30 and 60 minutes after fatty meal (FM) ingestion.
Results: In control group GBEF at 30-minute and at 60-minute after FM ingestion were 69.54%±21.04% and 84.26%±11.41% respectively while in patients group GBEF at 30-minute  was 61.21%±16.01%  and at 60-minute was 80.22%±12.57%. No significant difference was noticed between control and patient groups. GBEF didn't show significant difference between different groups based on the number of gallbladder stone, severity of chronic inflammatory (lymphoplasma) cell infiltration, wall thickness and evidence of fibrosis in the gallbladder wall.
Conclusion: Our data are against the diagnostic value of the GBEF as measured by FM-CS in the workup of patients with CC. Thus, interpretation of GBEF should take the proper clinical context into consideration.