Advanced Biomedical Imaging Seminar - "Accelerating Edited MRS"

Richard Edden, PhD is an Associate Professor in the Johns Hopkins Medicine Department of Radiology and Radiological Science. His research focuses on the development of new magnetic resonance spectroscopy (MRS) methods and the application of existing methods to investigate the brain. Dr. Edden received his undergraduate and graduate degree in the chemistry from the University of Cambridge as a scholar of Selwyn College. He completed a fellowship at the Schools of Biosciences and Chemistry at Cardiff University in Wales. Dr. Edden’s research is concerned with both the development of new MRS methods and the application of existing methods to investigate the brain. One technical area of his research relates to the behavior of coupled spin systems (such as lactate, citrate, GABA, and Glx) during localized spectroscopy experiments. Specifically, he investigates the interplay between finite-bandwidth slice-selective pulses and the chemical shift difference between coupled spins.

"Edited Magnetic Resonance Spectroscopy (MRS) substantially increases the number of metabolites that can be quantified in the human brain, by tailoring acquisitions to detect individual metabolites, such as the inhibitory neurotransmitter GABA. It is increasingly widely used, but the scope of edited clinical studies is limited by long acquisitions (~10 min) that proceed at a rate of one metabolite and one region per experiment.  We have recently developed a number of methods, including MEGA-PRIAM, which uses multiband excitation and SENSE-like reconstruction to acquire edited measurements in more than one location at a time, and HERMES, which uses a Hadamard editing encoding strategy to acquire edited measurements from more than one metabolite at a time. By multiplexing edited acquisitions, accelerations of more than fourfold are possible, with the potential to transform the kinds of edited MRS studies that can be proposed."