Maximizing SNR per unit time in diffusion MRI with multiband T-Hex spirals

© 2023 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine..

PURPOSE: The characterization of tissue microstructure using diffusion MRI (dMRI) signals is rapidly evolving, with increasing sophistication of signal representations and microstructure models. However, this progress often requires signals to be acquired with very high b-values (e.g., b > 30 ms/μm2 ), along many directions, and using multiple b-values, leading to long scan times and extremely low SNR in dMRI images. The purpose of this work is to boost the SNR efficiency of dMRI by combining three particularly efficient spatial encoding techniques and utilizing a high-performance gradient system (Gmax  ≤ 300 mT/m) for efficient diffusion encoding.

METHODS: Spiral readouts, multiband imaging, and sampling on tilted hexagonal grids (T-Hex) are combined and implemented on a 3T MRI system with ultra-strong gradients. Image reconstruction is performed through an iterative cg-SENSE algorithm incorporating static off-resonance distributions and field dynamics as measured with an NMR field camera. Additionally, T-Hex multiband is combined with a more conventional EPI-readout and compared with state-of-the-art blipped-CAIPIRINHA sampling. The advantage of the proposed approach is furthermore investigated for clinically available gradient performance and diffusion kurtosis imaging.

RESULTS: High fidelity in vivo images with b-values up to 40 ms/μm2 are obtained. The approach provides superior SNR efficiency over other state-of-the-art multiband diffusion readout schemes.

CONCLUSION: The demonstrated gains hold promise for the widespread dissemination of advanced microstructural scans, especially in clinical populations.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:91

Enthalten in:

Magnetic resonance in medicine - 91(2024), 4 vom: 01. März, Seite 1323-1336

Sprache:

Englisch

Beteiligte Personen:

Engel, Maria [VerfasserIn]
Mueller, Lars [VerfasserIn]
Döring, André [VerfasserIn]
Afzali, Maryam [VerfasserIn]
Jones, Derek K [VerfasserIn]

Links:

Volltext

Themen:

Diffusion MRI
Journal Article
Magnetic field monitoring
Multiband
Simultaneous multi-slice
Spiral imaging

Anmerkungen:

Date Completed 05.02.2024

Date Revised 22.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/mrm.29953

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM366471805