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Model‐based reconstruction framework for correction of signal pile‐up and geometric distortions in prostate diffusion MRI

Usman, M; Kakkar, LS; Kirkham, APS; Arridge, SR; Atkinson, D; (2019) Model‐based reconstruction framework for correction of signal pile‐up and geometric distortions in prostate diffusion MRI. Magnetic Resonance in Medicine , 81 (3) pp. 1973-1992. 10.1002/mrm.27547. Green open access

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Abstract

PURPOSE: Prostate diffusion‐weighted MRI scans can suffer from geometric distortions, signal pileup, and signal dropout attributed to differences in tissue susceptibility values at the interface between the prostate and rectal air. The aim of this work is to present and validate a novel model based reconstruction method that can correct for these distortions. METHODS: In regions of severe signal pileup, standard techniques for distortion correction have difficulty recovering the underlying true signal. Furthermore, because of drifts and inaccuracies in the determination of center frequency, echo planar imaging (EPI) scans can be shifted in the phase‐encoding direction. In this work, using a B0 field map and a set of EPI data acquired with blip‐up and blip‐down phase encoding gradients, we model the distortion correction problem linking the distortion‐free image to the acquired raw corrupted k‐space data and solve it in a manner analogous to the sensitivity encoding method. Both a quantitative and qualitative assessment of the proposed method is performed in vivo in 10 patients. RESULTS: Without distortion correction, mean Dice similarity scores between a reference T2W and the uncorrected EPI images were 0.64 and 0.60 for b‐values of 0 and 500 s/mm2, respectively. Compared to the Topup (distortion correction method commonly used for neuro imaging), the proposed method achieved Dice scores (0.87 and 0.85 versus 0.82 and 0.80) and better qualitative results in patients where signal pileup was present because of high rectal gas residue. CONCLUSION: Model‐based reconstruction can be used for distortion correction in prostate diffusion MRI.

Type: Article
Title: Model‐based reconstruction framework for correction of signal pile‐up and geometric distortions in prostate diffusion MRI
Open access status: An open access version is available from UCL Discovery
DOI: 10.1002/mrm.27547
Publisher version: https://doi.org/10.1002/mrm.27547
Language: English
Additional information: © 2018 The Authors. This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/).
Keywords: Geometric distortion, Diffusion, Prostate MRI, Signal pile-up
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 Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Medicine
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Medicine > Department of Imaging
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Medicine > Experimental and Translational Medicine
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Computer Science
URI: https://discovery.ucl.ac.uk/id/eprint/10056527
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