Single photon emission computerized tomography (SPECT) for estimates of liver and spleen volume

A simple procedure is described for estimates of liver and spleen volume using the imaging data obtained during single photon emission computerized tomography ( SPECT ). In vitro studies were carried out to obtain correlation and regression coefficients for volume estimations. Using these regression coefficients, we estimated liver and spleen volumes in 50 patients. Phantom and organ volumes were also calculated from transmission computed tomography (TCT), whose results served as the reference procedure against which SPECT -determined volumes were compared. The influence of radiotracer uptake on scintigraphic volume predictions was also assessed. For the in vitro measurements, SPECT volumes predicted the true volumes with a coefficient of correlation of 0.997. When in vivo SPECT volumes were correlated with those obtained by TCT, a coefficient in excess of 0.9 was achieved. SPECT volume determinations proved to be influenced by organ uptake of tracer; high liver uptake and low spleen-to-liver ratios gave the best results. It is concluded that SPECT imaging offers access to rapid and exact volume estimation.