Multi-Center Evaluation of Feasibility of SPECT Measurement of Myocardial Blood Flow and Reserve

Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI), who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%) and are clinically indicated to have an MBF study. Research imaging will consist of a SPECT acquisition at the time of rest and stress radiotracer injection in addition to the standard (delayed) clinical stress/rest SPECT scan with 99mTc-tetrofosmin. This is an observational study; patients will be managed according to the standard clinical care of the local site. Where available, a CT scan will also be acquired for attenuation and/or scatter correction. Studies may be one day (rest/stress or stress/rest) or two day (rest and stress on separate days) All studies will be analyzed locally but the raw data will also be anonymized and forwarded to the core facility for reprocessing. Central processing will allow comparison between sites and the repeat processing will provide an estimate of inter-operator variability in the measurements. The core lab will also compare the relative perfusion from immediate and delayed imaging for image quality and diagnostic accuracy (visual and quantitative).