Model-based iterative reconstruction for direct imaging with point spread function encoded echo planar MRI

Copyright © 2024 Elsevier Inc. All rights reserved..

BACKGROUND: Echo planar imaging (EPI) is a fast measurement technique commonly used in magnetic resonance imaging (MRI), but is highly sensitive to measurement non-idealities in reconstruction. Point spread function (PSF)-encoded EPI is a multi-shot strategy which alleviates distortion, but acquisition of encodings suitable for direct distortion-free imaging prolongs scan time. In this work, a model-based iterative reconstruction (MBIR) framework is introduced for direct imaging with PSF-EPI to improve image quality and acceleration potential.

METHODS: An MBIR platform was developed for accelerated PSF-EPI. The reconstruction utilizes a subspace representation, is regularized to promote local low-rankedness (LLR), and uses variable splitting for efficient iteration. Comparisons were made against standard reconstructions from prospectively accelerated PSF-EPI data and with retrospective subsampling. Exploring aggressive partial Fourier acceleration of the PSF-encoding dimension, additional comparisons were made against an extension of Homodyne to direct PSF-EPI in numerical experiments. A neuroradiologists' assessment was completed comparing images reconstructed with MBIR from retrospectively truncated data directly against images obtained with standard reconstructions from non-truncated datasets.

RESULTS: Image quality results were consistently superior for MBIR relative to standard and Homodyne reconstructions. As the MBIR signal model and reconstruction allow for arbitrary sampling of the PSF space, random sampling of the PSF-encoding dimension was also demonstrated, with quantitative assessments indicating best performance achieved through nonuniform PSF sampling combined with partial Fourier. With retrospective subsampling, MBIR reconstructs high-quality images from sub-minute scan datasets. MBIR was shown to be superior in a neuroradiologists' assessment with respect to three of five performance criteria, with equivalence for the remaining two.

CONCLUSIONS: A novel image reconstruction framework is introduced for direct imaging with PSF-EPI, enabling arbitrary PSF space sampling and reconstruction of diagnostic-quality images from highly accelerated PSF-encoded EPI data.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:109

Enthalten in:

Magnetic resonance imaging - 109(2024) vom: 29. Apr., Seite 189-202

Sprache:

Englisch

Beteiligte Personen:

Meyer, Nolan K [VerfasserIn]
In, Myung-Ho [VerfasserIn]
Black, David F [VerfasserIn]
Campeau, Norbert G [VerfasserIn]
Welker, Kirk M [VerfasserIn]
Huston, John [VerfasserIn]
Halverson, Maria A [VerfasserIn]
Bernstein, Matt A [VerfasserIn]
Trzasko, Joshua D [VerfasserIn]

Links:

Volltext

Themen:

Echo planar imaging
Image reconstruction
Journal Article
Low-rank
Point spread function

Anmerkungen:

Date Completed 09.04.2024

Date Revised 09.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.mri.2024.03.009

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369801881