I have had 2 hida scans 6 weeks apart. the 1st failed to visualize the gb after 4 hrs, the 2nd with cck = 53% ef. no narcotics, etc. why difference?

Variable: Sometimes the gall bladder does not fill because the sphincter at the end of the bike duct stays open. The gall bladder only passively fills. Sometimes we need to give morphine to constrict it and force the gall bladder to fill and sometimes we dont.

Poor preparation: Most likely answer is that you may not may fasted long enough the first time

Fasting?: If you were fasting for a little while prior to the first scan, the gallbladder was full of bile and not allowing the radiotracer to get into the gallbladder.

Patient preparation: Your second scan with a gallbladder ejection fraction of 53% is normal. Nonvisualization of gb after 4 hours is usually related to an obstruction of the cystic duct or a gb full of biliary stone or sludge, giving cholecystitis. In your case though it was probably related to a rather long fasting period before the test allowing your gb to retain bile and preventing 99mtc-hida to enter the gb.

Several reasons: If gallbladder is not visualized within 4 hours after injection it indicates that there is either cholecystitis or cystic duct obstruction. Any treatment between studies.HIDA scans can be falsely positive when the gallbladder is not filling in the absence of cholecystitis, severe liver disease, parenteral nutrition, hyperbilirubinemia, inadequate fasting, and alcohol and opiate abuse.