Improving multi-pinhole CZT myocardial perfusion imaging specificity without changing sensibility by using adapted prefilter parameters

Abstract

Background Meta-analysis show the diagnostic performance of cardiac dedicated multi-pinhole CZT (cadmium-zinc-telluride) myocardial perfusion imaging (MPI) with a sensibility around 0.9 and a specificity around 0.7. The aim of the present study is to explore a simple method to generate less artefact on MPI using single photon emission computed tomography (SPECT) and to enhance specificity without changing sensibility. Results From October 2018 to March 2019, 200 patients who underwent SPECT with [99mTc]Tc-tetrofosmin were prospectively recruited: 100 patients with ischemia or necrosis diagnosis (first arm), and 100 patients with myocardial reversible SPECT artefact (second arm). Each SPECT was explored using two image process based on a Butterworth prefilter: the original image processing (treatment A) with a cut-off frequency equals to 37% of the Nyquist frequency and order equals to 7, and a second image processing (treatment B) with a cut-off frequency equals to 25% of the Nyquist frequency and order equals to 5. For each patient, sum stress or rest score with and without septum (SSRS and SSRSws) were calculated with the two treatments. No significant statistical difference between SSRSa and SSRSb was identified for the first arm (P=0.54) and the relative difference ∆r was -0.5 ± 11.1 % (CI95 -2.6–1.8). We found a significant statistical difference between SSRSa and SSRSb for the second arm (p < 0.0001). Conclusion In conclusion, using a prefilter cut-off frequency equal to 25% of the Nyquist frequency before iterative reconstruction generates less artefact and improves myocardial SPECT specificity without affecting sensibility compared with the original treatment.