Specific absorption rate implications of within-scan patient head motion for ultra-high field MRI.

ABSTRACT:

Purpose

This study investigates the implications of all degrees of freedom of within-scan patient head motion on patient safety.

Methods

Electromagnetic simulations were performed by displacing and/or rotating a virtual body model inside an 8-channel transmit array to simulate 6 degrees of freedom of motion. Rotations of up to 20° and displacements of up to 20 mm including off-axis axial/coronal translations were investigated, yielding 104 head positions. Quadrature excitation, RF shimming, and multi-spoke parallel-transmit excitation pulses were designed for axial slice-selection at 7T, for seven slices across the head. Variation of whole-head specific absorption rate (SAR) and 10-g averaged local SAR of the designed pulses, as well as the change in the maximum eigenvalue (

SUBMITTER: Kopanoglu E 

PROVIDER: S-EPMC7396298 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature