Evaluation of basis function and linear least squares methods for generating parametric blood flow images using 15O-water and positron emission tomography

Purpose: Parametric analysis of O-15-water positron emission tomography (PET) studies allows determination of blood flow (BF), perfusable tissue fraction (PTF), and volume of distribution (V-d) with high spatial resolution. In this paper the performance of basis function and linear least squares methods for generating parametric flow data were evaluated. Procedures: Monte Carlo simulations were performed using typical perfusion values for brain, tumor, and heart. Clinical evaluation was performed using seven cerebral and 10 myocardial O-15-water PET studies. Basis function (BFM), linear least squares (ILLS), and generalized linear least squares (GLLS) methods were used to calculate BF, PTF, or V-d. Results: Monte Carlo simulations and human studies showed that, for low BF values (< 1 ml min(-1) ml(-1)), BF, PTF, and V-d were calculated with accuracies better than 5% for all methods tested. For high BF (> 2 ml min(-1) ml(-1)), use of BFM provided more accurate V-d compared with (G)LLS. Conclusions: In general, BFM provided the most accurate estimates of BF, PTF, and V-d.