Noninvasive imaging of myocardial blood flow recovery in response to stem cell intervention

The recovery of myocardial blood flow is a major indicator of the effectiveness of cell-based therapies for ischemic heart diseases including myocardial infarction. Blood flow (also called perfusion) of the heart muscle can be noninvasively measured via imaging methods such as ultrasound, positron emission tomography (PET), or magnetic resonance imaging (MRI). Here, we describe an MRI technique, namely, spin labeling, to measure the volumetric blood flow (mL/min/g) in the heart. Specifically, we demonstrate how impaired blood flow in the infarcted region of the heart was recovered transiently (≥ 2 weeks) after the injection of endothelial progenitor cells.