Quantitative image reconstruction using position-dependent scatter correction in single photon emission CT

Elimination of scattered photons from acquired counts is necessary for reconstructing a quantitative SPECT (single photon emission computed tomography) image. To perform correction of the scattered photons, the authors have developed a novel scatter correction method considering the local scatter fraction at each pixel in a planar image and evaluated its validity by simulations using numerical phantoms. In the present work, they evaluate the parameters used in the correction method, i.e., the width of a main window and subwindows, and the location of the subwindows. They show the results of experiments using a myocardial phantom and preliminary clinical studies using a commercially available gamma-camera system equipped with special hardware. In the clinical studies, a new Tc-99m myocardial perfusion imaging agent (P-53) was used. These results show that quantitative measurement of activity in clinical study is possible without adding data acquisition/processing time