Cardiac motion correction for improving perfusion defect detection in cardiac SPECT at standard and reduced doses of activity.

In this study, we investigated the potential benefit of cardiac motion correction for improving the detectability of perfusion defects. We considered a post-reconstruction motion correction (PMC) approach in which the image motion between two cardiac gates is obtained with optical flow estimation (OFE). 
 
 In the experiments, we demonstrated the proposed PMC-OFE approach on a set of clinical acquisitions from 194 subjects. We quantified the detectability of perfusion defects in the reconstructed images by using the total perfusion deficit (TPD) scores, calculated by the clinical software tool QPS, and conducted a receiver-operating-characteristic (ROC) study to obtain the detection performance. Besides imaging with conventional standard dose, we also evaluated the approach for reduced dose SPECT imaging where the imaging dose was retrospectively reduced to 50%, 25%, and 12.5% of the standard dose. The proposed PMC-OFE approach achieved at each dose level higher area-under-the-ROC-curve (AUC) for perfusion defect detection than the traditional approach of using ungated data (Non-MC) (p-value < 0.05); in particular, with half dose, PMC-OFE achieved AUC=0.813, which is comparable to Non-MC with standard dose (AUC = 0.795). Moreover, the proposed PMC-OFE approach also outperformed the "Motion Frozen" (MF) method implemented in the clinical quantitative gated SPECT (QGS) software. The proposed PMC-OFE approach could improve the spatial resolution of the rec...

Source: Physics in Medicine and Biology - January 16, 2019 Category: Physics Authors: Song C, Yang Y, Wernick MN, Pretorius PH, Slomka PJ, King MA Tags: Phys Med Biol Source Type: research