[Study on the evaluation of total and regional liver function using 99mTc-GSA dynamic SPECT].

To evaluate regional and total liver function, 99mTc-GSA dynamic SPECT was studied in 58 patients with various liver disease and 5 normal volunteers. Using dual-head gamma camera, 60 projection data (90 seconds/rotation) were acquired to obtain SPECT imaging. Forty continuous SPECT were obtained for 60 minutes. Time activity curve (TAC) of each voxel was created. The TAC was assumed to be equally the function of C(t) = Cmax (l-e-kt). The liver uptake rate (K value) was calculated using the least squares method. The product of K value and functional volume of each voxel was defined as liver functional index and the sum of the indices was defined as total liver functional index. The total liver functional index had good correlation with various liver function test, HH15, LHL15, and the index showed significant difference between each group of Child-Pugh's liver dysfunction stage. Because of unnecessariness of setting up the ROI, this method is simple and the result is no difference among operators. Three-dimensional liver functional index map exactly shows regional liver function. So that, this method seems to be useful for predicting the residual liver function after hepatectomy.