Spleen/liver ratio in RES-scintigraphy. A comparison between posterior registration and emission computed tomography.

The relative uptake of the spleen compared with the liver in RES-scintigraphy is of diagnostic significance. The spleen/liver (S/L) ratio from a posterior registration is most often used. The high S/L ratios found in earlier reports could well be explained by splenomegaly. Posterior registration as well as emission computed tomography was performed in 29 patients. In cases with splenomegaly the S/L ratio derived from the posterior registration was about the same as from emission computed tomography. In cases without splenomegaly the S/L ratios found by emission computed tomography were significantly higher and more correct than the values recorded from a posterior registration.