[Study of heart region of interest setting method in the hepatic functional reserve index of (99m)tc-diethylenetriamine pentaacetic Acid-galactosyl human serum albumin].

In this study we analyzed the influence of region of interest (ROI) selection on the uptake ratio of the liver to the liver plus heart at 15 min (LHL15) during (99m)Tc-galactosyl human serum albumin (GSA) scintigraphy and determined the optimal ROI by evaluating the individual effects of different ROIs in the heart on LHL15. Twenty patients were randomly selected from those who had undergone (99m)Tc-GSA scintigraphy GSA between April 2008 and June 2009. The liver body (L/B) ratio, liver uptake 15 min (LU15), and LHL15 were analyzed and compared among the following ROIs: entire heart, both ventricles, right ventricle, and left ventricle. There were significant differences in the L/B ratio and LU15 values among the different ROIs. However, LHL15 showed a tendency to shift toward a normal value when the size of the ROI was small (only the right or left ventricle), resulting in a lack of distinction between normal and abnormal LHL15 values. Furthermore, setting the entire heart as the ROI was difficult and reproducibility was low. Our results suggest that the use of both ventricles as the ROI provides optimal LHL15 values during (99m)Tc-GSA scintigraphy.