Prof. Phillip Zhe Sun - CMIC/WEISS Joint Seminar Series

Invited Speaker:  Prof. Phillip Zhe Sun - Emory National Primate Research Center

Title: Quantitative in vivo CEST MRI – from phantoms, animal models to patients

Abstract:

Chemical exchange saturation transfer (CEST) MRI offers a sensitive means for detecting dilute labile protons and microenvironmental properties. It has been applied to map brain metabolites (epilepsy), amide proton content (tumor), and tissue pH (stroke). Despite its versatility, CEST quantification has been challenging. This difficulty is because the CEST measurement depends not only on the underlying CEST system but also on the scan protocols, including RF saturation amplitude, duration, repetition time, and flip angle. Furthermore, because nearly all CEST measurements have been carried out at the non-equilibrium state, widely adopted quantification methods are prone to errors, including multi-pool Lorentzian fitting, omega plot analysis, and dissection of T1 contribution. It is also not straightforward to standardize multi-site/vendor experiments. The recent development of quasi-steady-state (QUASS) CEST provides a novel strategy to overcome these challenges. In short, the QUASS CEST algorithm reconstructs the desired equilibrium state from the experimental measurement, enabling expedited scans without losing the CEST contrast, and is uniquely suited to standardize multi-site studies. Most importantly, the QUASS algorithm transforms CEST-weighted toward fully quantitative CEST (qCEST) MRI. I will present emerging CEST data from phantoms, rodent models, and patients, demonstrating the practical use of QUASS-augmented CEST imaging. 

Bio:

Phillip Sun is a Professor of Radiology and Imaging Sciences at Emory University School of Medicine. He also directs the Imaging Center Emory National Primate Research Center. Dr. Sun earned his Ph.D. from the Division of Health Sciences and Technology at Harvard University and MIT in 2003. He spent three years at Johns Hopkins University for his postdoctoral training before joining the Martinos Center in 2006. Dr. Sun was promoted to Associate Professor of Radiology in 2014 before joining Emory University in 2018. His research has focused on the development and applications of imaging, with particular emphasis on using MRI to study brain metabolism, function, and structure. His lab played a critical role in advancing chemical exchange saturation transfer (CEST) and diffusion kurtosis imaging (DKI), including technical development, validation, and application in disorders such as acute stroke, tumor, and epilepsy. His research has been sponsored by the NIH, American Heart Association (AHA), and Pharmaceutical Companies. He has authored over 100 peer-reviewed articles, including the recent quasi-steady-state (QUASS) CEST MRI.

Chair: Mina Kim