Iterative static field map estimation for off-resonance correction in non-Cartesian susceptibility weighted imaging.

ABSTRACT:

Purpose

Patient-induced inhomogeneities in the magnetic field cause distortions and blurring during acquisitions with long readouts such as in susceptibility-weighted imaging (SWI). Most correction methods require collecting an additional ΔB0$$ \Delta {\mathrm{B}}_0 $$ field map to remove these artifacts.

Theory

The static ΔB0$$ \Delta {\mathrm{B}}_0 $$ field map can be approximated with an acceptable error directly from a single echo acquisition in SWI. The main component of the observed phase is linearly related to ΔB0$$ \Delta {\mathrm{B}}_0 $$ and the echo time (TE), and the relative impact of non- ΔB0$$ \Delta {\mathrm{B}}_0 $$ terms becomes insignificant with TE$$ \mathrm{TE} $$ >20 ms at 3 T for a well-tuned system.

Methods

The main step is to combine and unfol

SUBMITTER: Daval-Frerot G 

PROVIDER: S-EPMC9545844 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature