Chapter 40 - Quantitative Noninvasive Estimation of rCBF by Using [ 15 O]Water and PET

This chapter proposes a method to estimate rCBF by using [ 15 O]water and positron emission tomography (PET). The theoretical basis of the method is based on the principle of inert gas exchange between capillary blood and tissue in a single compartment model for CBF measurement using [ 15 O]-labeled H 2 O, developed by Kety. This method generates rCBF images on a pixel-by-pixel basis, and it is based on the acquisition of sequences of images with correction of nonlinearity of brain tissue counts. In this study, [ 15 O]water PET scans were performed on 13 normal human volunteers and continuous sampling from the radial artery was conducted to generate functional CBF images according to the invasive catheterization method. The effect on distribution volume was also evaluated and the real and calculated flows were compared. Although, there is dependence in the whole brain and the assumption that the V d is 1 for all regions, this method was demonstrated to provide accurate estimation of rCBF and may simplify the brain activation studies.