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Motion‐robust and blood‐suppressed M 1‐optimized diffusion MR imaging of the liver
Author(s) -
Zhang Yuxin,
PeñaNogales Óscar,
Holmes James H.,
Hernando Diego
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27735
Subject(s) - waveform , reproducibility , nuclear magnetic resonance , diffusion mri , nuclear medicine , robustness (evolution) , sensitivity (control systems) , weighting , effective diffusion coefficient , diffusion , magnetic resonance imaging , physics , mathematics , medicine , chemistry , radiology , statistics , biochemistry , quantum mechanics , voltage , electronic engineering , gene , engineering , thermodynamics
Purpose To develop motion‐robust, blood‐suppressed diffusion‐weighted imaging (DWI) of the liver with optimized diffusion encoding waveforms and evaluate the accuracy and reproducibility of quantitative apparent diffusion coefficient (ADC) measurements. Methods A novel approach for the design of diffusion weighting waveforms, termed M 1‐optimized diffusion imaging (MODI), is proposed. MODI includes an echo time‐optimized motion‐robust diffusion weighting gradient waveform design, with a small nonzero first‐moment motion sensitivity ( M 1) value to enable blood signal suppression. Experiments were performed in eight healthy volunteers and five patient volunteers. In each case, DW images and ADC maps were compared between acquisitions using standard monopolar waveforms, motion moment‐nulled ( M 1‐nulled and M 1– M2 ‐nulled) waveforms, and the proposed MODI approach. Results Healthy volunteer experiments using MODI showed no significant ADC bias in the left lobe relative to the right lobe ( p < .05) demonstrating robustness to cardiac motion, and no significant ADC bias with respect to monopolar‐based ADC measured in the right lobe ( p < .05), demonstrating blood signal suppression. In contrast, monopolar‐based ADC showed significant bias in the left lobe relative to the right lobe ( p < .01) due to its sensitivity to motion, and both M 1‐nulled and M 1– M2 ‐nulled‐based ADC showed significant bias ( p < .01) due to the lack of blood suppression. Preliminary patient results also suggest MODI may enable improved visualization and quantitative assessment of lesions throughout the entire liver. Conclusions This novel method for diffusion gradient waveform design enables DWI of the liver with high robustness to motion and suppression of blood signals, overcoming the limitations of conventional monopolar waveforms and moment‐nulled waveforms, respectively.