BAR-DETECTOR WITH EXTENDED FIELD-OF-VIEW FOR A MODULAR SPECT SYSTEM

In the conventional centroid position estimation method, the effective field of view (Fov) of a scintillation bar-detector cannot be extended beyond the centers of the two outside PMTs. To extend the FOV, we have implemented statistical position estimation on a bar-detector with blackened end surfaces. Maximum Likelihood (ML) and Minimum Square Error (MSE) position estimation look up tables (LUTS) were calculated from experimentally measured histogram data. Both statistical estimators provide a 14 cm FOV on a 16 cm bar, with 4 to 6 mm FWHM within the FOV. In contrast, the centroid method provides a 10 cm FOV on a conventional bar-detector. In order to reduce the size of LUTs and, memory requirements, we have demonstrated the feasibility of using local, 2-D LUTs for position estimation. using statistical position estimation methods and scatter-free sources we were able to extend the FOV beyond the conventional limit to utilize 90% of the bar-detector area.