Avoiding full corrections in dynamic SPECT images impacts the performance of SPECT myocardial blood flow quantitation.

INTRODUCTION

This study investigated the performance of SPECT myocardial blood flow (MBF) quantitation lacking full physical corrections (All Corr) in dynamic SPECT (DySPECT) images.

METHODS

Eleven healthy normal volunteers (HVT) and twenty-four patients with angiography-documented CAD were assessed. All Corr in Tc-sestamibi DySPECT encompassed noise reduction (NR), resolution recovery (RR), and corrections for scatter (SC) and attenuation (AC), otherwise no correction (NC) or only partial corrections. The performance was evaluated by quality index (R ) and blood-pool spillover index (FBV) in kinetic modeling, and by rest flow (RMBF) and stress flow (SMBF) compared with those of All Corr.

RESULTS

In HVT group, NC diminished 2-fold flow uniformity with the most degraded quality (15%-18% reduced R ) and elevated spillover effect (45%-50% increased FBV). Consistently higher RMBF and SMBF were discovered in both groups (HVT 1.54/2.31 higher; CAD 1.60/1.72; all P < .0001). Bland-Altman analysis revealed positive flow bias (HVT 0.9-2.6 mL/min/g; CAD 0.7-1.3) with wide ranges of 95% CI of agreement (HVT NC -1.9-7.1; NR -0.4-4.4; NR + SC -1.1-4.3; NR + SC + RR -0.7-2.5) (CAD NC -1.2-3.8; NR -1.0-2.8; NR + SC -1.0-2.5; NR + SC + RR -1.1-2.6).

CONCLUSIONS

Uncorrected physical interference in DySPECT images can extensively impact the performance of MBF quantitation. Full physical corrections should be considered to warrant this tool for clinical utilization.