(99m)Tc sulfur colloid and (99m)Tc mebrofenin hepatobiliary functional liver imaging in normal and diabetic rats.

OBJECTIVES To use (99m)Tc sulfur colloid ((99m)Tc-SC) and (99m)Tc mebrofenin ((99m)Tc-BrIDA) to study liver function in normal and diabetic rats. MATERIALS AND METHODS Radionuclide imaging was performed on 2 groups of rats, using (99m)Tc-SC for one group and (99m)Tc-BrIDA for the other (20 rats per group) before and after induction of diabetes mellitus (DM) using streptozotocin administration (55 mg/kg i.p.). Dynamic acquisition was obtained for 1 h after the injection of 37 MBq of radiotracer. For the (99m)Tc-SC group, organ/tissue uptake was determined by drawing regions of interest (ROI) over the heart, liver, spleen and also the whole body (WB). The ratio of the ROI of each organ to the WB ROI was calculated. For (99m)Tc-BrIDA, ratios of cumulative count rates in liver, liver parenchyma, biliary tree and abdomen ROI to a WB ROI were also calculated. Statistical analysis was performed to compare the ratios of organ/tissue uptake to WB uptake before and after DM induction using the paired t test. RESULTS (99m)Tc-SC uptake ratios (means ±SD) showed a lower liver-to-WB uptake ratio (0.75 ± 0.05) in the rats after DM induction compared to baseline (0.81 ± 0.06), while the cardiac blood pool showed higher uptake ratios in the rats after DM induction (p = 0.026). For (99m)Tc-BrIDA, there was no significant difference in radiotracer uptake ratios obtained from the rats before and after DM induction (p = 0.41). CONCLUSION Using functional liver imaging, there was a statistically significant decrease in the liver phagocytic/reticuloendothelial system function after DM induction, as evidenced by decreased (99m)Tc-SC liver uptake and increased blood pool compared to prediabetes, while the hepatobiliary function remained unchanged after DM induction using (99m)Tc-BrIDA imaging.