Feasibility of shortened scan acquisition time with IQ-SPECT technology using SMARTZOOM(TM) collimator in myocardial perfusion imaging.

Objectives: IQ-SPECT technology uses cardiac-specific SMARTZOOM(TM) collimator that can reduce the time required to acquire myocardial perfusion images to half (14 seconds/view) of a standard SPECT procedure. This study aimed to further shorten the scan acquisition time (7 seconds/view) using the SMARTZOOM(TM) collimator without compromising the image quality.

Methods: This prospective observational study involved 50 patients (39 men and 11 women) who underwent myocardial perfusion studies using the SMARTZOOM(TM) collimator. The scans were acquired in 7 seconds/view (Group A) and 14 seconds/view (Group B). Attenuation-corrected (AC), non-attenuation-corrected (NAC), and polar maps were generated for both groups using the QGS/QPS software. The groups were qualitatively and quantitatively compared in terms of image quality, relative uptake score, summed scores, total perfusion deficit, and left ventricular ejection fraction (LVEF).

Results: The image quality of both groups was comparable in the AC studies, whereas Group B was superior to Group A in the NAC studies. All images exhibited an image quality score of ≥3, which suggested adequate image quality. The mean LVEF values were 62.16 and 64.34 in Groups A and B, respectively (p-value 0.326). A strong positive correlation was observed between the two datasets (Pearson's r=0.59). The mean summed score in the AC images was 7.5 in both groups (p-value 0.49), and in the NAC images, the scores were 7.68 in Group A and 7.46 in Group B (p-value 0.46). The mean total perfusion deficits calculated using the 17-segment models were 11% and 16% in Group A and Group B, respectively, for the AC images (p-value 0.143) and 11.2% and 16.5% in Group A and Group B, respectively, for the NAC images (p-value 0.135). Significant differences were not noted in the calculation of the relative uptake score in segments 1- 17 for the AC and NAC images in Groups A and B.

Conclusion: The findings from this study indicate that further shortening of the scan acquisition time to 7 seconds/view is possible in myocardial perfusion imaging using the SMARTZOOM(TM) collimator without compromising the scan quality and the results, thus improving patient comfort.