Multicenter Trial of High-Speed Versus Conventional Single-Photon Emission Computed Tomography Imaging

Objectives

This prospective, multicenter trial compared quantitative results of myocardial perfusion imaging and function using a high-speed single-photon emission computed tomography (SPECT) system with those obtained with conventional SPECT.

Background

A novel SPECT camera was shown in a pilot study to detect a similar amount of myocardial perfusion abnormality compared with conventional SPECT in one-seventh of the acquisition time.

Methods

A total of 238 patients underwent myocardial perfusion imaging with conventional and high-speed SPECT at 4 U.S. centers. An additional 63 patients with a low pre-test likelihood of coronary artery disease underwent myocardial perfusion imaging with both technologies to develop method- and sex-specific normal limits. Rest/stress acquisition times were, respectively, 20/15 min and 4/2 min for conventional and high-speed SPECT. Stress and rest quantitative total perfusion deficit, post-stress left ventricular end-diastolic volume, and ejection fraction were derived for the 238 patients by the 2 methods.

Results

High-speed stress and rest total perfusion deficit correlated linearly with conventional SPECT total perfusion deficit (r = 0.95 and 0.97, respectively, p < 0.0001), with good concordance in the 3 vascular territories (kappa statistics for the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery were 0.73, 0.73, and 0.70, respectively; >90% agreement). The percentage of ischemic myocardium by both imaging modalities was significantly larger in patients with a high coronary artery disease likelihood than in those with a low and intermediate likelihood (p < 0.001). The average amount of ischemia was slightly but significantly larger by high-speed SPECT compared with conventional SPECT in high-likelihood patients (4.6 ± 4.6% vs. 3.9 ± 4.0%, respectively; p < 0.05). Post-stress ejection fraction and end-diastolic volume by the 2 methods were linearly correlated (r = 0.89 and 0.97, respectively).

Conclusions

The high-speed SPECT technology provides quantitative measures of myocardial perfusion and function comparable to those with conventional SPECT in one-seventh of the acquisition time.