Perfusable tissue index (PTI) is a marker of myocardial viability and requires acquisition of transmission, 15O-CO, and 15O-H2O scans. The aim of this study was to generate parametric PTI images from a 15O-H2O PET/CT scan without an additional 15O-CO scan.
Data from 20 patients undergoing both 15O-H2O and 15O-CO scans were used, assessing correlation between PTI based on 15O-CO (PTICO) and on fitted blood volume fractions (PTIVb). In addition, parametric PTIVb images of 10 patients undergoing 15O-H2O PET/CT scans were generated using basis-function methods and compared with PTIVb obtained using nonlinear regression. Simulations were performed to study the effects of noise on PTIVb.
Correlation between PTICO and PTIVb was high (r2 = 0.73). Parametric PTIVb correlated well with PTIVb obtained using nonlinear regression (r2 = 0.91). Simulations showed low sensitivity to noise (coefficient of variation < 10% at 20% noise).
Parametric PTI images can be generated from a single 15O-H2O PET/CT scan.
2011. Vol. 52, no 5, 745-749 p.