Thallium 201 (Tl) myocardial perfusion imaging (MPI) with a novel fast cardiac camera versus conventional camera (SPECT)

Objectives D-SPECT (Spectrum-Dynamics, Israel) is a novel solid state cardiac camera, previously shown to detect similar amount of perfusion abnormality with Tc-MIBI as conventional SPECT in up to one eighth the acquisition time. We compared Tl MPI with fast D-SPECT and SPECT.

Methods 52 patients (60.9+11.4 years, 30 men) had Tl stress/redistribution and were imaged for 6 min and 15 min on D-SPECT and SPECT, respectively. Images were visually interpreted using a 17-segment model and a 5-point scale, obtaining summed stress (SSS) and rest (SRS) scores (SSS>3 abnormal). Quantitative analysis of stress Tl D-SPECT and SPECT was performed by QPS (Cedars Sinai, CA), using specific normal limits for each imaging method, to assess the total perfusion defect (TPD, %).

Results All 11 abnormal SPECT studies were abnormal on D-SPECT. SSS and SRS on SPECT and D-SPECT strongly correlated (r=0.97 for both, p<0.0001). Bland-Altman plots showed good agreement, a mean difference of -0.676 (95% CI: 0.093-1.187) for SSS and -0.627 (95%CI: 0.171-1.064) for SRS. D-SPECT TPD correlated strongly to SPECT TPD (r=0.846, p<0.0001) and Bland-Altman analysis showed good agreement (mean difference 0.77, 95% CI: -0.756-1.674). In 7 patients with recent coronary angiography (CA) D-SPECT correlated better with CA in 3 (2 showing ischaemia not seen on SPECT, 1 true negative D-SPECT and false positive SPECT), in 1 case SPECT correlated better with CA and in 3 cases both modalities were similar.

Conclusions Visual and quantitative analysis of Tl MPI with fast D-SPECT correlate excellently to conventional SPECT and to CA in selected cases.