Magnetic Resonance Imaging Technology Development

National Institute Of Neurological Disorders And Stroke

Investigators

Linked publications, trials & patents

Abstract

Work has continued on planning for the arrival of the 11.7T magnet (now slated to be shipped back to NIH in October), with particular emphasis on human safety aspects. Test objects have been designed to allow measurement of tissue heating associated with MRI signal generation, and a prototype, single radiofrequency (RF) transmitter channel with on-coil signal amplification has been tested as part of the construction of a transmit array that will overcome some of the anticipated difficulties in MRI signal generation in deep brain areas. A whole-brain transmit coil is nearing completion and has been demonstrated to allow nearly uniform RF transmit fields even when driven from a single RF channel. Although much of this uniformity will be lost when imaging human brain, the coil will provide a good starting point for imaging superficial areas of the brain, in particular when combined with surface coil signal reception. A novel technique to measure brain myelin content has been developed and tested at 3T and 7T. The method uses low levels of RF compared to existing methods and will therefore be applicable at 11.7T, where it will provide improved sensitivity. Measurements on brain tissues and life marmosets are underway to establish the methods specificity to myelin as well as, more generally, to help understand the contributions of myelin to MRI contrast at high field.