Assessment of Myocardial Blood Flow with Cardiac PET Perfusion Imaging

Myocardial blood flow (MBF) assessment in conjunction with PET perfusion imaging has become commonplace in cardiac PET laboratories. The clinical value is well described and validated for PET. This includes placing a patient in a very low risk category for CAD and CAD-related events if both perfusion and MBF are normal, identifying missed epicardial and microvascular CAD in patients with normal perfusion but abnormal MBF and suggest failure of vasodilation in patients with normal perfusion but no increase in blood flow at stress. MBF in patients with abnormal perfusion can help discriminate severity of epicardial CAD. Of importance, patients with global reduction in MBF and no epicardial CAD by catheterization likely have microvascular disease, an established cause of anginal symptoms especially in diabetic and/or female patients. SPECT MBF may be possible with specialized instrumentation (CZT cameras) but has not yet been implemented widely.