Effects of B₀ eddy currents on imaging isocenter shifts in 0.35-T MRI-guided radiotherapy (MR-IGRT) system.

ABSTRACT:

Purpose

The purpose of this study was to measure gantry angle-related eddy currents in a 0.35-T MRI-Linac and determine if B₀ (zeroth order) eddy currents are the primary cause of gantry angle-dependent imaging isocenter shifts vs other potential causes like B₀ inhomogeneities and gradient (first order) eddy currents. For conventional Cartesian acquisitions, B₀ eddy currents can cause imaging isocenter shifts along both phase encode and readout directions. Gradient eddy currents can cause spatial distortion along both the phase encode and readout directions. Center frequency offsets can cause imaging isocenter shifts along the readout direction that vary with readout gradient polarity.

Methods

MRI-related eddy currents and imaging isocenter s

SUBMITTER: Curcuru AN 

PROVIDER: S-EPMC8292055 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature