Nguyen Thanh D, Deh Kofi, Monohan Elizabeth, Pandya Sneha, Spincemaille Pascal, Raj Ashish, Wang Yi, Gauthier Susan A
Department of Radiology, Weill Cornell Medical College, New York, New York, USA.
Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, USA.
Magn Reson Med. 2016 Aug;76(2):456-65. doi: 10.1002/mrm.25877. Epub 2015 Aug 29.
To develop and measure the reproducibility of 4-min whole brain myelin water fraction (MWF) mapping using fast acquisition with spiral trajectory and T2prep (FAST-T2) sequence at 3T.
Experiments were performed on phantoms, 13 volunteers, and 16 patients with multiple sclerosis. MWF maps were extracted using a spatially constrained non-linear algorithm. The proposed adiabatic modified BIR-4 (mBIR-4) T2prep was compared with the conventional composite T2prep (COMP). The effect of reducing the number of echo times (TEs) from 15 to 6 (reducing scan time from 10 to 4 min) was evaluated. Reproducibility was assessed using correlation analysis, coefficient of variation (COV), and Bland-Altman plots.
Compared with COMP, mBIR-4 provided more accurate T2 in phantoms and better MWF maps in human brains. Reducing the number of TEs had a negligible effect on MWF map quality, with a regional MWF difference of <0.8%. Regional MWFs obtained by repeated scans showed excellent correlation (R = 0.99), low COV (1.3%-2.4%), and negligible bias within ±1% limits of agreement. On a voxel-wise basis, the agreement remained strong (correlation R = 0.89 ± 0.03, bias = 0.01% ± 0.29%, limits of agreement = [-3.35% ± 0.73%, 3.33% ± 0.61%]).
Whole brain MWF mapping with adiabatic FAST-T2 is feasible in 4 min and provides good intrasite reproducibility. Magn Reson Med 76:456-465, 2016. © 2015 Wiley Periodicals, Inc.
利用3T场强下的螺旋轨迹快速采集和T2预脉冲（FAST-T2）序列，开发并测量4分钟全脑髓磷脂水含量（MWF）成像的可重复性。
对体模、13名志愿者和16例多发性硬化症患者进行实验。使用空间约束非线性算法提取MWF图。将所提出的绝热改良BIR-4（mBIR-4）T2预脉冲与传统的复合T2预脉冲（COMP）进行比较。评估将回波时间（TE）数量从15减少到6（将扫描时间从10分钟减少到4分钟）的效果，并使用相关分析、变异系数（COV）和Bland-Altman图评估可重复性。
与COMP相比，mBIR-4在体模中提供了更准确的T2，在人脑成像中提供了更好的MWF图。减少TE数量对MWF图质量的影响可忽略不计，区域MWF差异<0.8%。重复扫描获得的区域MWF显示出极好的相关性（R = 0.99）、低COV（1.3%-2.4%）且在±1%一致性界限内偏差可忽略不计。在体素层面，一致性仍然很强（相关性R = 0.89±0.03，偏差 = 0.01%±0.29%，一致性界限 = [-3.35%±0.73%，3.33%±0.61%]）。
使用绝热FAST-T2进行全脑MWF成像在4分钟内是可行的，并且具有良好的位点内可重复性。《磁共振医学》76:456-465，2016年。©2015威利期刊公司。
