[Impact of Different Acquisition Modes on Image Quality and Quantitative Accuracy for Bone SPECT Using Ordered Subset Conjugate-gradient Minimizer]

We evaluated the effect of different xSPECT Bone acquisition methods on image quality and quantitative accuracy. A mixed bone-equivalent solution set to 250 HU and ^99mTc was filled with the SIM² Bone phantom. The xSPECT Bone acquisitions were performed with the step and shoot (SS) mode and two continuous modes (continuous_view, continuous_total) of the times per view, and the total acquisition times were the same as the SS mode. The radioactive concentration ratio of normal bone and tumor was set to 1 : 6. The reconstructed images were evaluated using uniformity, contrast, spatial resolution, recovery coefficient (RC) of the tumor part, and detectability. The detectability score (DS), an overall evaluation of detectability, was calculated from the results of uniformity and contrast. Uniformity of SS, continuous_view, and continuous_total methods was 29.4%, 17.4%, and 11.1%, respectively. Spatial resolution, RC, and detectability were similar among the SS mode and two continuous modes; however, the continuous modes showed good uniformity and contrast compared with the SS mode. In addition, the detectability of the continuous mode was equal to or superior to that of the SS mode.