학술논문

Using synthetic MR images for distortion correction
Document Type
article
Source
Subject
Biomedical and Clinical Sciences
Biological Psychology
Clinical and Health Psychology
Neurosciences
Psychology
Clinical Research
Pediatric
Biomedical Imaging
Bioengineering
Adult
Humans
Child
Adolescent
Image Processing
Computer-Assisted
Algorithms
Magnetic Resonance Imaging
Echo-Planar Imaging
Brain
Artifacts
fMRI
EPI
Distortion correction
Field map
Registration
Clinical Sciences
Cognitive Sciences
Biological psychology
Clinical and health psychology
Language
Abstract
Functional MRI (fMRI) data acquired using echo-planar imaging (EPI) are highly distorted by magnetic field inhomogeneities. Distortion and differences in image contrast between EPI and T1-weighted and T2-weighted (T1w/T2w) images makes their alignment a challenge. Typically, field map data are used to correct EPI distortions. Alignments achieved with field maps can vary greatly and depends on the quality of field map data. However, many public datasets lack field map data entirely. Additionally, reliable field map data is often difficult to acquire in high-motion pediatric or developmental cohorts. To address this, we developed Synth, a software package for distortion correction and cross-modal image registration that does not require field map data. Synth combines information from T1w and T2w anatomical images to construct an idealized undistorted synthetic image with similar contrast properties to EPI data. This synthetic image acts as an effective reference for individual-specific distortion correction. Using pediatric (ABCD: Adolescent Brain Cognitive Development) and adult (MSC: Midnight Scan Club; HCP: Human Connectome Project) data, we demonstrate that Synth performs comparably to field map distortion correction approaches, and often outperforms them. Field map-less distortion correction with Synth allows accurate and precise registration of fMRI data with missing or corrupted field map information.