Evaluation of hepatic perfusion and function with modified hepatobiliary scintigraphy

Abstract

The quantitative relationship between changes in portal vein pressure and the perfusion index was studied, and hepatocellular function was evaluated. A modified protocol of hepatobiliary dynamic scintigraphy with Tc-99m-labeled ethylene hepatobiliary iminodiacetic acid (EHIDA) was performed in 37 patients with hepatic cirrhosis and 12 healthy controls. In 18 patients, the portal vein pressure (PVP) was measured intra-operatively during the portal vein bypass procedure. The portal vein perfusion index (PVI) was obtained by a two-compartment model of hepatic perfusion. A three-compartment model was applied in the hepatocellular extracted and excreted time-radioactivity curves, and the hepatic functional index was calculated including the hepatic uptake index (UI), the mean residual index (MRI), the uptake speed index (UsI), the descent speed index (DsI), the peak uptake (PU), and the peak time (PT) of hepatic uptake. These function indices in the cirrhotic patients were compared to the indices in the healthy controls with a two-sided t-test; specifically, the PU (18.94 ± 6.80 vs. 29.67 ± 18.98, P < 0.01), UI (0.84 ± 5.99 vs. 18.41 ± 13.87, P < 0.05), and UsI (0.58 ± 0.39 vs. 1.23 ± 0.81, P < 0.01) were slower in patients with hepatic cirrhosis compared with the healthy controls. The PT (16.83 ± 4.89 vs. 10.95 ± 2.79, P < 0.001) and MRI (5.93 ± 2.96 vs. 2.74 ± 0.97, P < 0.001) were more prolonged and the DsI (0.07 ± 0.09 vs. 0.18 ± 0.14, P < 0.01) was less compared to controls. The PVI were significantly higher in cirrhotic patients than in controls (46.17 ± 7.83 vs. 29.07 ± 5.71, P < 0.001), and the PVI correlated to the PVP ( r = 0.79, P < 0.01). In conclusion, modified quantitative hepatobiliary dynamic scintigraphy can evaluate the changes of portal vein blood flow and monitor hepatocellular function, in which the portal vein blood flow can estimate portal vein pressure.