Performance of myocardial perfusion imaging using multi-focus fan beam collimator with resolution recovery reconstruction in a comparison with conventional SPECT

Abstract

<br />Objective: IQSPECT is an advanced high-speed SPECT modality for performing myocardial perfusion imaging (MPI), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. The aim of this study was to compare IQSPECT compared with conventional SPECT interms of performance based on standard clinical protocols. In addition, we examined the concordance between conventional and IQSPECT in patients with coronary artery disease (CAD). <br />Methods: Fifty-three patients undergoing rest-gated MPI for the evaluation of known or suspected coronary artery disease were enrolled in this study. In each patient, conventional SPECT (99mTc-tetrofosmin, 9.6 min; 201Tl, 12.9 min) was performed, immediately followed by IQSPECT, using a short acquisition time (4.3 min for 99mTc-tetrofosmin and 6.2 min for 201Tl). A quantitative analysis was performed on an MPI polar map using a 20-segment model of the left ventricle. An automated analysis by gated SPECT was carried out to determine the left ventricular volume and function, including the end-diastolic volume, end-systolic volume and left ventricular ejection fraction (LVEF). The degree of concordance between conventional SPECT and IQ-SPECT images was evaluated according to linear regression and Bland-Altman analyses. <br />Results: The segmental percent uptake exhibited a significant correlation between IQSPECT and conventional SPECT (<em>P</em><0.05). The mean differences in 99mTc‐tetrofosmin studies were 1.1±6.6% (apex), 2.8±5.7% (anterior wall), 2.9±6.2% (septal wall),4.9±6.7% (lateral wall), and 1.8±5.6% (inferior wall). Meanwhile, regarding the 201Tl‐SPECT studies, these values were 1.6±6.9%, 2.0±6.6%, 2.1±5.9%, 3.3±7.2%, and 2.4±5.8%, respectively. Although the mean LVEF in IQ‐SPECT tended to be higher than that observed in conventional SPECT (conventional SPECT=64.8±11.8% and IQSPECT=68.3±12.1% for 99mTc‐tetrofosmin; conventional SPECT= 56.0±11.7% and IQSPECT=61.5±12.2% for 201Tl), quantitative parameters were not significantly different between IQ‐SPECT and conventional SPECT. <br /> <br />Conclusion: According to the 99mTc‐tetrofosmin and 201Tl protocols, IQ‐SPECT images were comparable to and in agreement with conventional SPECT images. Our results suggest that IQ‐SPECT is a useful technology for MPI SPECT, and can lead to an increase in scan efficiency and patient comfort. <br />