A method of dynamic scatter correction for direct 4?dimensional PET parametric imaging / 中华核医学与分子影像杂志

ABSTRACT

Objective To propose a method of dynamic scatter correction for direct 4-dimensional (4D) PET parametric image reconstruction. Methods Scatter correction for direct 4D PET parametric im-age reconstruction was achieved by extending 3-dimensional (3D) static single scatter simulation (SSS) into 4D dynamic SSS with the help of spatiotemporal cubic polynomial interpolation. The 2 h-serotonin transporter tracer 11 C-2-(2-(dimethylaminomethyl)phenylthio)-5-fluoromethylphenylamine (AFM) brain List mode data of 3 volunteers were obtained from a human brain-dedicated high resolution research tomograph (HRRT) PET scanner. Parametric images (K1 and VT ) were reconstructed by both conventional frame-based method (FM) and direct 4D method. Estimated scatter fractions by both methods were compared. Paired t test was used to analyze the data. Results Scatter fractions derived from FM and direct 4D method were 30.1％(6. 35×107 / (2.11× 108 )), 32.0％ (6.82× 107 / (2.13× 108 )) and 34.4％ (7.22× 107 / (2.10× 108 )), 30. 0％(6.33×107 / (2.11×108 )), 33.3％(7.10×107 / (2.13×108 )) and 34.1％(7.16×107 / (2.10×108 )) for the three subjects, respectively (t = -0.002, P>0.05). Scatter fractions obtained by the two methods were comparable. There was no significant difference between K1(FM (0.51±0.11) ml·min-1 ·cm-3 , 4D (0.48±0.09) ml·min-1 ·cm-3) and VT (FM (24.77±11.80) ml/ cm3, 4D (27.85±12.65) ml/ cm3) in the two methods (t values -0.01, -0.97, both P>0.05). Conclusion The proposed dynamic scatter cor-rection method can be used for direct 4D parametric imaging and make it feasible for clinical use.