Is Iterative Reconstruction an Improvement Over Filtered Back Projection in Processing Gated Myocardial Perfusion SPECT?

ABSTRACT

The impact of iterative reconstruction (IR) on myocardial perfusion imaging (MPI) interpretation and functional results is under investigated. We evaluated the effect of IR on the interpretation and functional results of MPI compared with filtered back-projection (FBP). Material and Methods: Sixty patients with previously acquired MPI were randomly selected. Studies were processed using FBP and 2D ordered-subsets expectation-maximization (OSEM). Two physicians interpreted the images after IR and FBP processing. Results were confirmed by coronary angiography and/or clinical course. Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were calculated with IR and FBP. Results: The sensitivity, specificity, positive and negative predictive values and accuracy of physician 1 were 95%, 87%, 80%, 97%, and 90% with FBP and 100%, 80%, 72%, 100%, and 87% with IR. For physician 2, they were 95%, 95%, 91%, 97%, and 95% with FBP and 81%, 95%, 90%, 90%, and 90% with IR. There were no statistically significant differences between physicians’ interpretations (P=0.71 for FBP and 0.09 for IR). There was good correlation between IR and FBP calculated LVEF (r=0.98), EDV (r=0.99), and ESV (r=0.99) but significant difference per patient (P=0.02, 0.03 and 0.02, respectively). Conclusion: There is no statistically significant difference in interpretation of MPI with IR versus FBP but there were statistically significant differences in functional results.

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