Motion-compensated diffusion encoding in multi-shot human brain acquisitions: Insights using high-performance gradients.

Autor: Michael ES; Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland., Hennel F; Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland., Pruessmann KP; Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2024 Aug; Vol. 92 (2), pp. 556-572. Date of Electronic Publication: 2024 Mar 05.
DOI: 10.1002/mrm.30069
Abstrakt: Purpose: To evaluate the utility of up to second-order motion-compensated diffusion encoding in multi-shot human brain acquisitions.
Methods: Experiments were performed with high-performance gradients using three forms of diffusion encoding motion-compensated through different orders: conventional zeroth-order-compensated pulsed gradients (PG), first-order-compensated gradients (MC1), and second-order-compensated gradients (MC2). Single-shot acquisitions were conducted to correlate the order of motion compensation with resultant phase variability. Then, multi-shot acquisitions were performed at varying interleaving factors. Multi-shot images were reconstructed using three levels of shot-to-shot phase correction: no correction, channel-wise phase correction based on FID navigation, and correction based on explicit phase mapping (MUSE).
Results: In single-shot acquisitions, MC2 diffusion encoding most effectively suppressed phase variability and sensitivity to brain pulsation, yielding residual variations of about 10° and of low spatial order. Consequently, multi-shot MC2 images were largely satisfactory without phase correction and consistently improved with the navigator correction, which yielded repeatable high-quality images; contrarily, PG and MC1 images were inadequately corrected using the navigator approach. With respect to MUSE reconstructions, the MC2 navigator-corrected images were in close agreement for a standard interleaving factor and considerably more reliable for higher interleaving factors, for which MUSE images were corrupted. Finally, owing to the advanced gradient hardware, the relative SNR penalty of motion-compensated diffusion sensitization was substantially more tolerable than that faced previously.
Conclusion: Second-order motion-compensated diffusion encoding mitigates and simplifies shot-to-shot phase variability in the human brain, rendering the multi-shot acquisition strategy an effective means to circumvent limitations of retrospective phase correction methods.
(© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)
Databáze: MEDLINE
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