Imaging of liver function with dedicated animal dynamic pinhole scintigraphy in rats

Background Non-invasive evaluation of liver function in small animal models remains a challenge. Hepatobiliary scintigraphy (HBS) enables the assessment of total and regional liver function for both uptake and excretion in larger species. Aim To validate quantitative liver function assessment with dedicated pinhole HBS in rats. To illustrate an application of this technique, liver function was assessed in two surgical models of liver regeneration. Methods HBS was performed in 12 rats with Tc-99m-mebrofenin on a dedicated animal pinhole gamma camera. The hepatic uptake rate was calculated twice by different observers to establish a normal range and the reproducibility of processing. The degree of hepatocellular injury and synthesis function were assessed by serum liver tests. Liver function was compared with liver weight. Subsequently, three groups of three rats were scanned on three separate days to assess the reproducibility of HBS. Finally, to illustrate an application of this technique, liver function was assessed in two surgical models of liver regeneration. Results HBS in rats was feasible without mortality. The mean liver uptake rate was 77.29 +/- 1.29% center dot min(-1). Calculation of the liver uptake (%center dot min(-1)) was highly reproducible (r=0.95, P < 0.001). there was a good correlation between liver weight and function measured by HBS at baseline and after partial resection (r=0.94, P < 0.001). Conclusion HBS offers a unique combination of functional liver uptake and excretion assessment with the ability to determine the liver function reserve before and after an intervention in rats. Nucl Med Commun 26:1005-1012 (c) 2005 Lippincott Williams & Wilkins.