Comparison of full-time iterative myocardial perfusion studies vs. half-time myocardial perfusion studies using Astonish

Objectives Half-time Myocardial Perfusion studies (MPS) using Astonish software were compared to the full-time MPS using Iterative reconstruction to determine any difference in quality.

Methods 50 patients were imaged with a full-time acquisition of 30 sec/frame and a half-time acquisition of 15 sec/frame simultaneously. Full-time studies were processed using NorthShore’s standard Iterative filter and half-time studies were processed using an Astonish filter. All studies were processed through myometrix, QGS and QPS programs. Quantitatively, MPS were compared using the QPS summed stress scores (SSS), summed rest scores (SRS), summed difference scores (SDS) and the QGS left ventricular ejection fraction (LVEF). Qualitatively, a nuclear cardiologist performed a blind comparison assessing the 2 sets of myometrix slices using a grading scale of qualitatively better, same or worse.

Results The nuclear cardiologist categorized 96% of the half time Astonish MPS as better, 2% of the full time Iterative MPS as better, and 2% of the MPS sets as the same. 96% of the patients had a change in their SSS or SRS. 84% of the patients had a change in their LVEF. Utilizing the student-t test, it was determined that the difference in SSS had a p-value of 0.0254, the difference in the SRS had a p-value of 0.1702, and the difference in the SDS had a p-value of 0.0128. The difference in the LVEF had a p-value of 0.4063.

Conclusions Utilizing these p-values, we determined that there was a significant difference between the Iterative full-time and the Astonish half-time in the SSS and the SDS, but there was not a significant difference in the SRS or the LVEF. The Nuclear Cardiologist graded Astonish half time studies as qualitatively better.