Determination of the spleen-blood partition coefficient for water with oxygen-15-water and oxygen-15-carbon dioxide dynamic PET steady-state methods.

Abstract

Regional splenic blood flow (SBF) was quantified by PET using a steady-state method with 15O-carbon dioxide. SBFs were determined using 104 tomographic planes obtained from 49 patients. When the spleen-blood partition coefficient for water (p) was > or = 0.85, significant correlations (p < 0.005) were found between SBF values determined by the steady-state and dynamic methods. The best correlation between SBFs determined by the two methods (r = 0.571) was found when p = 0.93. The best regression line, however, was thought to be the line when p = 0.93. The regression line between SBF calculated by the steady-state method (y) and SBF determined by the dynamic method (x) was y = 0.57 x + 0.03 with an F ratio of 48.75 (d.f. = 103, p = 5.0 x 10(-8)%, by ANOVA) when p = 0.92. A quick evaluation of SBF can be made by using the newly defined regression line.