Standardization of "In-House fatty meal" methodology for cholescintigraphy

This study was aimed at standardizing the "In-House fatty meal" methodology in cholescintigraphy and to determine gall bladder ejection fraction (GBEF) with this standardized meal. This is a prospective case-control study where 61 patients having right upper quadrant pain and postprandial bloating and 59 healthy volunteers were included. They underwent (99m)Tc-mebrofenin fatty meal cholescintigraphy following a standard protocol. Dynamic acquisitions over 120 min were done, with a fatty meal being given between 45- and 60-min. Gallbladder emptying kinetics was studied by assessing the time activity curves and calculation of GBEFs were made at 30-min, 45-min, and at 60-min and assessed. The GBEF at 30-min was 74.42% ± 8.26% (mean ± standard deviation), at 45-min was 82.61% ± 6.5%, and at 60-min was 89.37% ± 4.48% in the volunteer group. The lower limit of GBEF in volunteers at 30-min was 58%, 45-min was 69%, and at 60-min was 81%. Receiver operating characteristic (ROC) analysis showed that 30-min GBEF provided the best separation between healthy and diseased subjects with an area under curve of 0.952 (95% confidence interval = 0.914-0.989). The lower limit of GBEF at 30-min was 58%. An in-House standard fatty meal could be a reproducible alternative to cholecystokinin as it is well-tolerated. Based on ROC curve analysis, we propose that 30-min GBEF provides good separation between healthy and diseased people with this in-House fatty meal. Hence, dynamic acquisitions beyond 30-min postingestion of the fatty meal may not be warranted.