Influence of Reconstruction Methods on Regional Wall Motion Abnormalities During Gated SPECT Myocardial Perfusion Imaging

Accurate assessment of regional wall motion abnormalities (RWMA) is essential for diagnosing coronary artery disease. The quality of image reconstruction in gated SPECT myocardial perfusion imaging (MPI) can significantly influence diagnostic accuracy. <b>Methods:</b> We retrospectively analyzed 100 patients who underwent gated SPECT MPI, including 25 normal and 75 abnormal cases stratified into mild, moderate, and severe defects groups. Images were reconstructed using filtered backprojection (FBP) and iterative reconstruction (IR) with varying iteration-subset settings. RWMA was visually assessed using a 20-segment model. Statistical agreement between methods was analyzed. <b>Results:</b> No significant differences were found between FBP and IR in normal and mild MPI groups. However, in moderate and severe cases, IR with 4 iterations × 6 subsets and 4 iterations × 8 subsets reclassified multiple patients into more severe RWMA categories, demonstrating higher diagnostic sensitivity compared with FBP (<i>P</i> < 0.0001). <b>Conclusion:</b> Optimized IR parameters (particularly 4 iterations × 6 subsets and 4 iterations × 8 subsets) improve the detection of RWMA in moderate to severe coronary artery disease compared with FBP. Incorporating IR into routine MPI protocols may enhance clinical decision-making and patient outcomes.