TY - JOUR T1 - Spatial and Energy Resolutions Measurements for C-SPECT JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 218 LP - 218 VL - 59 IS - supplement 1 AU - Dale Stentz AU - Poopalasingam Sankar AU - Roger Arseneau AU - Wei Chang AU - Joel Karp AU - Scott Metzler Y1 - 2018/05/01 UR - http://jnm.snmjournals.org/content/59/supplement_1/218.abstract N2 - 218Purpose: First Spatial and Energy Resolutions Measurements for the Complete C-SPECT Detector System Objectives: The aim of this work is to present the first results for the completed C-SPECT detector: a dedicated cardiac SPECT/TCT system for clinical research. C-SPECT uses 14 NaI(Tl) pixelated detector modules arranged in a thorax-contouring shape with photo detection handled by 130 single-anode 51 mm diameter PMTs. The system provides axial coverage of 168 mm and angular coverage of 220° from the optimal center in our imaging volume. We characterize the status of the detector by first providing a basic flood map as well as noting the performance of our data acquisition system. We perform spatial resolution measurements that characterize the system’s intrinsic detector resolution before computing the system resolution with the full collimator. In addition, we measure energy resolution of the system in each of our detectors. Methods: We acquired flood data (no collimator) using Na22 to evaluate if our detector is fully working. This also provides the data for pixel identification and verification. Next, we acquired a scan using a Co57 point source at high count-rate (total input ~1 MHz) and use this data to measure the energy resolution of each detector module. We perform a spatial resolution measurement by using a tungsten pinhole (0.5 mm diameter aperture) placed against the detector light-shielding wall and locating the Co57 source ~150 mm away. The pinhole source projection onto the detector provides axial and transverse profile widths, which are measured and converted to millimeters by measuring the local crystal-to-crystal distance in Anger logic space. This measurement can then be repeated to sample multiple positions to confirm basic uniformity of the result. Results: Our flood scans show a fully working detector system and our acquisition system handles simultaneously writing data from all 14 detector modules. The Co57 flood gives the energy resolution measurements in each module, but require module-by-module tuning to achieve the single-module performance of 11 ± 1% FWHM (full with at half maximum) based on a fully tuned single module system previously tested prior to assembly. For the spatial resolution, we conducted an initial measurement, which gives transverse & axial resolution (FWHM) ~10% larger than our physical 2.5 by 3.0 mm pixel size. Additional experiments will be performed to measure the resolution as a function of position on the detector and to confirm module-to-module uniformity. Conclusions: We have performed our first tests and performance studies of the assembled and working C-SPECT system. It is fully operational with measurements in both the spatial and energy resolution. ER -