Department of Radiology

The Dynamic Multi-Coil Technique (DYNAMITE) -

A novel MR Imaging and B0 Shimming Concept

Christoph Juchem, PhD

Associate Professor

Departments of Biomedical Engineering and Radiology at Columbia University New York, NY

Wednesday, December 5, 2018

4:00 pm - 5:00 pm

Belfer Bldg. (413 E 69th St.) Room 1501 (15^th floor)

Refreshments will be served at 3:45 pm

All are welcome to attend

Abstract

Magnetic resonance imaging and spectroscopy allow the non-invasive measurement of brain anatomy and physiology, but excellent B0 magnetic field homogeneity is required for meaningful results. The correction of static magnetic field imperfections, so-called B0 shimming, is particularly demanding in the brain where air-tissue interfaces create complex and strong distortions.

            In my talk, I will present a novel technique for magnetic field modeling and shimming that is based on the combination of fields generated by a matrix of small, generic coils. This multi-coil approach enables the accurate generation of simple and complex magnetic field shapes in a flexible fashion. B0 shimming with the dynamic multi-coil technique (DYNAMITE) outperforms conventional methods based on spherical harmonic functions and provides unrivaled magnetic field homogeneity in mouse, rat and human brain. I will discuss the methodological aspects of DYNAMITE shimming and demonstrate its benefits for gradient-echo EPI. Along with the efficiency gains of DYNAMITE shimming compared to spherical harmonic approaches, the multi-coil concept has the potential to 1) replace conventional shim systems that are based on sets of dedicated SH coils and 2) allow optimal object-specific shim solutions similar to object-specific RF coils. The technology furthermore lends itself to spatial encoding. I will present MRI results, including concomitant imaging and B0 shimming, in which all fields are purely DYNAMITE-based.