Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI) and who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%). 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. Study end will be defined as completion of all SPECT imaging at rest and stress. Studies will be acquired at 6 initial sites with mixed prior experience at MBF imaging, to demonstrate feasibility of use in a clinical setting.

MBF was measured locally and at a core laboratory using commercially available software. The acquisition protocol was standardized between the local site and core laboratory. a one-day rest-stress protocol was used. Relative perfusion images were obtained after tracer injection. All raw study data were transferred to the core laboratory where processing was independently repeated by one reader to evaluate inter site processing consistency. Perfusion scores were compared with the measured MBF.

Additional acquisition time for the MBF acquisition. For each patient study, the time during which the patient was in the camera room for each imaging session was recorded along with the start times for each scan. From this data, the increase in time for MBF protocol compared with the time for a standard myocardial perfusion imaging protocol was determined.

Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI) and who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%). 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

SPECT Imaging with 99mTc-Tetrofosmin Research Imaging: This is an observational study; patients will be managed according to the standard clinical care of the local site. Study end will be defined as completion of all SPECT imaging at rest and stress. Studies will be acquired at 6 initial sites with mixed prior experience at MBF imaging, to demonstrate feasibility of use in a clinical setting.

MBF was measured locally and at a core laboratory using commercially available software. The acquisition protocol was standardized between the local site and core laboratory. a one-day rest-stress protocol was used. Relative perfusion images were obtained after tracer injection. All raw study data were transferred to the core laboratory where processing was independently repeated by one reader to evaluate inter site processing consistency. Perfusion scores were compared with the measured MBF.

Myocardial perfusion images were acquired from patients undergoing clinically indicated single photon emission computed tomography myocardial perfusion imaging. Patients were included if they were at least 18 years of age, had a body mass index of less than 40kg/m2, and were of intermediate to high pretest probability of coronary artery disease on a stable medication regimen. All 35 patients scanned were included in the study.

Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI) and who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%). 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

SPECT Imaging with 99mTc-Tetrofosmin Research Imaging: This is an observational study; patients will be managed according to the standard clinical care of the local site. Study end will be defined as completion of all SPECT imaging at rest and stress. Studies will be acquired at 6 initial sites with mixed prior experience at MBF imaging, to demonstrate feasibility of use in a clinical setting.