Sensitivity and resolution study of a small-field γ-Camera system on a tomographic level

• Main Authors: Mikeli, M., Rapsomanikis, A.-N, Thanasas, D., Menis, I., Stiliaris, E.
• Format: Conference Proceeding
• Language: English
• ISSN: 1082-3654; 2577-0829
• DOI: 10.1109/NSSMIC.2012.6551728

The sensitivity and the spatial resolution of a small-field γ-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 ) containing water solution of 99m Tc is used as a test phantom in the present work. A total of 24 projections covering the full angle region (0°-360°) are obtained with the γ-Camera system under examination. The planar information is further analyzed to reconstruct the tomographic images taking into account all off-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 different techniques (MLEM and accelerated ART) are used. The variety of the 99m Tc-volumes in the phantom with the given specific radioactivity and the phantom axial asymmetry, due to the different 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; they are also directly compared with ideal tomographic results acquired from the fully simulated γ-Camera system through GATE.