Comparison of the SSRB, MSRB, and FORE methods with the 3DRP algorithm using data from a high resolution PET scanner

The authors used the high-resolution prototype PET camera developed at MD Anderson Cancer Center (MDAPET) to scan a cylindrical uniform phantom, a cylindrical phantom with four hot small lesions in a warm background, and the Hoffman brain phantom. The MDAPET camera is a multiring scanner having no septa that allows for three-dimensional (3D) data acquisition. The acquired data were used to test several methods of rebinning 3D-projection data into two-dimensional (2D) sinograms. For this study, first, the 3D data were reconstructed using the 3D-reprojection (3DRP) algorithm; then images were used as a reference for testing the rebinning methods. The methods the authors tested were single-slice rebinning (SSRB), multi-slice rebinning (MSRB), and Fourier rebinning (FORE). After the data were rebinned, the 2D filtered-backprojection (2DFB) or 2D ordered-subsets expectation-maximization (OSEM) algorithm was used for image reconstruction. Rebinning the 3D data and using a 2D reconstruction technique resulted in noise reduction when compared with 3DRP; however, it reduced the contrast recovery and also showed some degradation in spatial resolution. The results also indicated that for the authors´ prototype camera, the SSRB followed by 2DFB, which significantly reduces reconstruction time, provides a reasonable alternative to 3DRP