Accurate and efficient rapid acquisition early post-injection stress-first CZT SPECT myocardial perfusion imaging with tetrofosmin and attenuation correction.

Introduction: Myocardial perfusion imaging (MPI) protocols have not changed significantly despite advances in instrumentation and software. We compared an early post-injection, stress-first SPECT protocol to standard delayed imaging.

Methods: 95 patients referred for SPECT MPI were imaged upright and supine on a Spectrum Dynamics D-SPECT CZT system with CT attenuation correction. Patients received injection of Tc tetrofosmin at peak of regadenoson stress and were imaged. Early post-stress (mean 17 ± 2 minutes) and Standard 1-h delay (mean 61 ± 13 min). Three blinded readers evaluated images for overall interpretation, perceived need for rest imaging, image quality, and reader confidence. Laboratory efficiency was also evaluated.

Results: Blinded readers had the same response for the need for rest in 77.9% of studies. Studies also had the same interpretation in 89.5% of studies. Reader confidence was high (86.0% (Early) and 90.3% (Standard p = 0.52. Image quality was good or excellent in 87.4% Early vs 96.8% Standard (p = 0.09). Time between patient check-in and end of stress imaging was 104 ± (Standard) to 60 ± 18 minutes (Early) (p < 0.001).

Conclusion: Early post-injection stress-only imaging using CZT SPECT/CT appears promising with Tc-99m tetrofosmin with similar image quality, reader confidence, diagnosis, and need for a rest scan.