Effect of head motion on MRI B₀ field distribution.

ABSTRACT:

Purpose

To identify and characterize the sources of B₀ field changes due to head motion, to reduce motion sensitivity in human brain MRI.

Methods

B₀ fields were measured in 5 healthy human volunteers at various head poses. After measurement of the total field, the field originating from the subject was calculated by subtracting the external field generated by the magnet and shims. A subject-specific susceptibility model was created to quantify the contribution of the head and torso. The spatial complexity of the field changes was analyzed using spherical harmonic expansion.

Results

Minor head pose changes can cause substantial and spatially complex field changes in the brain. For rotations and translations of approximately 5 º and 5 mm, respectiv

SUBMITTER: Liu J 

PROVIDER: S-EPMC6239980 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature