Harvard Catalyst Profiles

Stony Brook University, Stony Brook, NY	BS	6/1971	Chemistry
Massachusetts Institute of Technology, Cambridge, MA	PhD	5/1976	Physical Chemistry
University of California, Berkeley, CA	Postdoctoral	1977	Physical Chemistry

The focus of my career has been the development of magnetic resonance technology and methodology, and the application of these to problems in chemistry, materials science and biomedicine. While a faculty member at the University of Cincinnati, the majority of my time was spent on graduate and undergraduate teaching, with the remainder spent primarily on research, mentoring and some administrative duties. At MGH the majority of my time is spent on research (including mentoring of postdoctoral fellows), and a small amount of time on administrative duties. I have mentored about 68 undergraduate research students, graduate students, postdoctoral fellows and visiting scientists. I have been a principal investigator on more than 28 grants and co-investigator or local PI on more than 27 others, an inventor on 6 issued patents, and a cofounder and chief scientific advisor of a startup company founded to commercialize solid state MRI for metabolic bone disease screening. According to Google Scholar my work (over 100 peer-reviewed journal articles, reviews, chapters and patents; over 200 abstracts) has been cited 5659 times as of October 2021 (1013 times since 2016).

Over nearly 45 years I have developed in my laboratory NMR spectrometers and MRI scanners and their associated components and software, and continue to do so today. This experience includes designing and building complete spectrometers and imagers and associated RF probes and coils. In the Martinos Center at MGH I have been the Principal Investigator of four Shared Instrumentation Grants and played significant roles in several other instrumentation grants.

A recent research interest is applications of MRI Therapy, a novel concept wherein the scanner plays a therapeutic—rather than merely diagnostic—role by means of the controlled and spatially directed application of RF heating to ablate or coagulate tissue. We recently established MR-mediated radiofrequency ablation (MR-RFA) as the first application of this technology, and demonstrated it with liver ablations in live pigs. Recent work has extended these studies to endovascular coagulation as an alternative to coiling for repair of vascular defects.

Another recent project involves real time device tracking using MR microcoils in conjunction with PET-MRI scanning. A methodology I first introduced in 1986 (abstract 6), rapid tracking of small MR coils is a common method for tracking the position of devices within the MRI scanner in real time with update rates approaching 100 times per second. We have used microcoil tracking to continuously follow head motion during PET scanning in a PET-MR scanner for the purpose of correcting PET image motion artifacts. In an offshoot of my longstanding research interest in solid state MR, we introduced a highly accurate method for PET attenuation correction based on solid state MRI in PET-MR scanning.

In ongoing work, we have developed a compact extremity MRI scanner based on a novel cryogen-free tilted superconducting magnet intended for multinuclear solid state MRI measurements of bone matrix and mineral as a radiation-free information-rich screening technique for metabolic bone disease. The scanner is also capable of conventional MRI.

Two new projects are Moving MRI and Low Field Cryogenic RF Coils. Moving MRI is a radically new imaging concept in which brain functional networks involving the vestibular system are studied with a magnet that moves in synchrony with a subject undergoing large scale bodily motion, such as tilts and rotations; Moving MRI may also be used to dynamically study the response of brain tissue to head impact. The cryogenic RF coil project uses the magnet cryocooler to chill the RF coil to cryogenic temperatures, thereby improving image signal-to-noise ratio in low field MRI scanners.