Factor analysis for the quantification of renal cortical blood flow using O-15 water dynamic PET

The renal cortical blood flow is an important index for the estimation of kidney function. Positron emission tomography (PET) allows noninvasive and quantitative estimate of blood flow. We applied factor analysis to O-15 water dynamic renal PET images to extract pure arterial and renal cortical time activity curves (TACs) for the estimation of renal cortical blood flow. Microsphere experiment was also performed to validate the renal cortical blood flow by factor analysis. In all the cases, factor images and their TACs could be extracted successfully. Input function by factor analysis and by arterial blood sampling was nearly same, except for the delay and dispersion. The renal cortical blood flow by factor analysis was within normal range (1.23-2.46 ml/min/g). In microsphere study, the flow by factor analysis was 2.49±0.47 ml/min/g and by microsphere was 2.52±0.19 ml/min/g