Performance of a new iterative reconstruction algorithm for cardiac short-time single photon emission computed tomography: Preliminary results in an anthropomorphic cardiac phantom study

A new iterative reconstruction algorithms (WBR) has been recently proposed for cardiac SPECT. The WBR technology is based on an iterative technique, includes physical parameters such as LSF modelling, collimator parameters and variable radius orbit, all affecting SPECT resolution. Few data still exist on the comparison between filtered back-projection (FBP) and WBR. The aim of this study was to compare the performance of FBP and this new algorithm. An anthropomorphic cardiac phantom with cold insert simulating regional infarctions was used to compare FBP and WBR; SPECT were acquired at standard time/frame (ST) and half time/frame (FIT), with a standard isotope activity (SD) or with half activity (HD). The average FWHM of the simulated infarction of the cardiac phantom of SD-HT (65.7deg) and HD-ST (57.5deg) WBR SPECT were comparable to that of SD-ST FBP SPECT (65.3deg). However, regional differences were observed. The new reconstruction algorithm, applied to a cardiac SPECT acquisition, allows either for short time SPECT acquisitions or studies employing a reduced isotope activity. The former allows for an increased patient throughput and optimization of resources. The latter modality would also allow for a significant reduction in patients' as well as operators' radiation exposure.