UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Mitigating susceptibility-induced distortions in high-resolution 3DEPI fMRI at 7T

Malekian, V; Graedel, NN; Hickling, A; Aghaeifar, A; Dymerska, B; Corbin, N; Josephs, O; ... Callaghan, MF; + view all (2023) Mitigating susceptibility-induced distortions in high-resolution 3DEPI fMRI at 7T. NeuroImage , 279 , Article 120294. 10.1016/j.neuroimage.2023.120294. Green open access

[thumbnail of 1-s2.0-S1053811923004457-main.pdf]
Preview
Text
1-s2.0-S1053811923004457-main.pdf - Published Version

Download (12MB) | Preview

Abstract

Geometric distortion is a major limiting factor for spatial specificity in high-resolution fMRI using EPI readouts and is exacerbated at higher field strengths due to increased B0 field inhomogeneity. Prominent correction schemes are based on B0 field-mapping or acquiring reverse phase-encoded (reversed-PE) data. However, to date, comparisons of these techniques in the context of fMRI have only been performed on 2DEPI data, either at lower field or lower resolution. In this study, we investigate distortion compensation in the context of sub-millimetre 3DEPI data at 7T. B0 field-mapping and reversed-PE distortion correction techniques were applied to both partial coverage BOLD-weighted and whole brain MT-weighted 3DEPI data with matched distortion. Qualitative assessment showed overall improvement in cortical alignment for both correction techniques in both 3DEPI fMRI and whole-brain MT-3DEPI datasets. The distortion-corrected MT-3DEPI images were quantitatively evaluated by comparing cortical alignment with an anatomical reference using dice coefficient (DC) and correlation ratio (CR) measures. These showed that B0 field-mapping and reversed-PE methods both improved correspondence between the MT-3DEPI and anatomical data, with more substantial improvements consistently obtained using the reversed-PE approach. Regional analyses demonstrated that the largest benefit of distortion correction, and in particular of the reversed-PE approach, occurred in frontal and temporal regions where susceptibility-induced distortions are known to be greatest, but had not led to complete signal dropout. In conclusion, distortion correction based on reversed-PE data has shown the greater capacity for achieving faithful alignment with anatomical data in the context of high-resolution fMRI at 7T using 3DEPI.

Type: Article
Title: Mitigating susceptibility-induced distortions in high-resolution 3DEPI fMRI at 7T
Location: United States
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.neuroimage.2023.120294
Publisher version: https://doi.org/10.1016/j.neuroimage.2023.120294
Language: English
Additional information: Copyright © 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Keywords: Distortion correction, EPI, High-resolution, Magnetisation transfer, Ultra high field, fMRI
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > UCL Queen Square Institute of Neurology > Imaging Neuroscience
URI: https://discovery.ucl.ac.uk/id/eprint/10175759
Downloads since deposit
15Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item