The overarching goal of this project is to develop and evaluate a single-tracer multiparametric positron emission tomography (PET) imaging solution for simultaneous imaging of blood flow and glucose metabolism using 18F-fluorodeoxyglucose (FDG) alone. The investigators working hypothesis is that quantitative blood flow can be extracted from dynamic 18F-FDG PET data by use of tracer kinetic modeling, in addition to glucose metabolism that 18F-FDG is conventionally used for.
Blood flow and glucose metabolism are two basic but vital physiological processes that are often dysregulated in major diseases. The phenomenon of flow-metabolism mismatch (or coupling) is of broad clinical and research significance. For example, (a) in ischemic cardiomyopathy, which affects several million people in the United States, myocardial flow-metabolism mismatch is clinically used for assessing tissue viability to select patients for surgical revascularization. Decreased blood flow but maintained glucose metabolism suggests the myocytes are still alive (while hibernating) and thus can benefit from revascularization; (b) In oncology, altered blood flow and glucose metabolism are closely related to two hallmarks of cancer - angiogenesis and increased cell metabolism. High metabolism-to-flow ratio may indicate cancer cells are resistant to therapy; (c) In the normal brain, cerebral blood flow and glucose metabolism are often coupled with each other but may become uncoupled in neurodegenerative diseases including Alzheimer's disease. There are critical interests and broad needs for integrated imaging of blood flow and metabolism in both clinical and research applications.
