Normal values for sincalide cholescintigraphy: comparison of two methods.

Area of Science:

• Gastroenterology
• Diagnostic Imaging
• Pharmacology

Background:

• Gallbladder ejection fraction (GBEF) is a key metric in assessing hepatobiliary function.
• Sincalide (cholecystokinin [CCK]) is commonly used to stimulate gallbladder contraction for GBEF measurement.
• Standardizing sincalide infusion protocols is essential for reliable GBEF determination.

Purpose of the Study:

• To determine normal gallbladder ejection fraction (GBEF) values using two sincalide (cholecystokinin [CCK]) infusion rates: 0.01 microg/kg over 3 minutes versus 0.01 microg/kg over 60 minutes.
• To compare the variability and clinical utility of GBEF measurements between the two infusion protocols.

Main Methods:

• Twenty healthy individuals underwent GBEF assessment via ultrasonography.
• GBEF was calculated following a 3-minute infusion and at 15-minute intervals during a 60-minute infusion of sincalide.
• Normal GBEF ranges were statistically derived using mean +/- 2 standard deviations.

Main Results:

• The 3-minute sincalide infusion resulted in significantly more variable GBEF measurements compared to the 45- and 60-minute intervals of the 60-minute infusion (P < .01, .002).
• The lower limit of the normal GBEF range (95% population) was 16.8% for the 3-minute infusion, versus 31% and 41% for the 45- and 60-minute intervals, respectively.
• Six of 20 healthy subjects (30%) showed GBEF < 35% with the 3-minute infusion, compared to only one subject with the 60-minute infusion.

Conclusions:

• A 3-minute sincalide infusion (0.01 microg/kg) is not suitable for establishing clinically useful normal GBEF ranges due to high response variability.
• A 60-minute infusion of sincalide at 0.01 microg/kg provides reliable and clinically applicable normal GBEF values at 45 and 60 minutes.