Sensitivity and Resolution Study of a Small-Field γ-Camera System on a Tomographic Level

Abstract

The sensitivity and the spatial resolution of a small-field ∞-Camera system based on a Position Sensitive Photomultiplier Tube (PSPMT) on a tomographic level are examined in this study. A cylindrical Gel-Phantom (d = 40 mm, h = 50 mm) with cylindro-conoidal tubes and capillaries (from 64 to 640 mm 3 in volume) containing water solution of 99m T c is used as a test phantom in the present work. A total of 24 projections covering the full angle region (0 0°3 60 0 ) are obtained with the ∞-Camera system under examination. The planar information is further analyzed to reconstruct the tomographic images taking into account all oAE-line corrections needed to remove barreloid deformations appearing at the edges of the Field-of-View. The reconstruction procedure is performed with iterative algorithms and for comparison reasons two diAEerent techniques (MLEM and accelerated ART) are used. The variety of the 99m T c-volumes in the phantom with the given specific radioactivity and the phantom axial asymmetry, due to the diAEerent radial distances of the tubes in the gel environment, allow a realistic characterization of the system's performance on a tomographic level. Obtained experimental results for the system sensitivity and spatial resolution are presented and discussed in this work.

Συνεισφορά της οπτικής τoμογραφίας OCT (optical computed tomography) στην μονοφωτονική τομοσπινθηρογραφία

“…[SPA04],[POL07],[THA09],[POL09],[MIK09],[RAP11]. The system contains the HAMAMATSU R2486-04 cylindrical PSPMT [HAM98] with a 50 mm field of view and provides an intrinsic spatial resolution of ~ 100 μm.…”