Spatial Resolution and Sensitivity of the Inveon Small-Animal PET

The Inveon small-animal PET scanner is characterized by a large, 127-mmaxial length and a 161-mmcrystal ring diameter. The as-sociated high sensitivity is obtained by using all lines of response (LORs) up to the maximum ring difference (MRD) of 79, for which the most oblique LORs form acceptance angles of 38.3 with transaxial planes. The result is 2 phenomena that are normally not encountered inPETscanners: aparallaxor depth-of-interaction effect in the axial direction and the breakdown of Fourier rebin-ning (FORE). Both effects cause a deterioration of axial spatial resolution. Limiting the MRD to smaller values reduces this axial blurring at the cost of sensitivity. Alternatively, 3-dimensional (3D) reconstruction techniques can be used in which the rebin-ning step is absent. The aim of this study was to experimentally determine the spatial resolution and sensitivity of the Inveon for its whole field of view (FOV). Methods: Spatial resolution an