title: Constancy and variability of gallbladder ejection fraction: impact on diagnosis and therapy.
abstract: The main objective of this study was to test the constancy and variability of gallbladder (GB) ejection fraction (EF) in long-term studies to (a) determine whether EF ever becomes normal once it is low, (b) determine how long it takes for the EF to become abnormal once it is found to be normal, (c) explore the cause of low EF, and (d) define objective parameters for biliary and nonbiliary abdominal pain.
  
  
  METHODS
  Fifty-two patients (42 women, 10 men) who underwent quantitative cholescintigraphy twice (total studies, 104), over a mean period of 38.54 mo between studies, were chosen for retrospective analysis. They were divided into the following groups: control (n = 13; nonbiliary abdominal pain), chronic acalculous cholecystitis (CAC) (n = 27; biliary abdominal pain), chronic calculous cholecystitis (CCC) (n = 6; biliary abdominal pain), and opioid (n = 6; nonbiliary abdominal pain). The last group had received an opioid before cholecystokinin-8 (CCK-8) infusion in one study but not in the other study. A GBEF value of > or =35% was considered normal with a 3-min infusion and > or =50% as normal with a 10-min infusion of CCK-8.
  
  
  RESULTS
  The mean GBEF value was reproducible between the 2 sequential studies in the control group (66.0% +/- 20.5% vs. 73.9% +/- 17.7%), CAC group (24.4% +/- 22.3% vs. 16.9% +/- 10.9%), and CCC group (20.8% +/- 20.9% vs. 27.5% +/- 34.5%) but not in the opioid group (14.8% +/- 14.6% vs. 56.5% +/- 31.7%). The severity of GBEF reduction in CAC increased with time: 7.2% +/- 8.1% within 12 mo, 16.1% +/- 14.9% in 13-47 mo, and 23.5% +/- 21.3% in 48-168 mo. None of the 27 patients with CAC developed a gallstone as detected by ultrasound during the study period. In 5 patients with CAC, a mean period of 52.6 +/- 28.9 mo was required for conversion from normal to a low EF. CCK-induced cystic duct spasm is the etiology for low EF in both CAC and CCC.
  
  
  CONCLUSIONS
  Normal and low GBEF values are reproducible in long-term studies. Once the EF reaches a low value, it does not return to normal, and a normal value requires many years to become abnormal. CCK-induced cystic duct spasm is the cause of low GBEF in CAC and CCC, and the severity of EF reduction is similar for both. Exclusion of opioid intake immediately before the study is critical before attributing a low GBEF value to an irreversible GB motor dysfunction.
authors.affiliation: Department of Nuclear Medicine, Tuality Community Hospital/Tuality Healthcare, Hillsboro, Oregon 97123, USA. GTKrishna@aol.com
authors.forename: Gerbail T
authors.initials: GT
authors.lastname: Krishnamurthy
authors.forename: Shakuntala
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Paul H
authors.initials: PH
authors.lastname: Brown
mesh_terms: D042101:Acalculous Cholecystitis / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002764:Cholecystitis / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D002908:Chronic Disease; D005260:Female; D005705:Gallbladder Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy; D016473:Gallbladder Emptying / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009294:Narcotics / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D009294:Narcotics