Neuromuscular Investigation Center, NMR Laboratory, Institute of Myology, Paris, France.
CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France.
J Magn Reson Imaging. 2021 May;53(5):1529-1538. doi: 10.1002/jmri.27381. Epub 2020 Sep 30.
Quantitative muscle MRI is a robust tool to monitor intramuscular fatty replacement and disease activity in patients with neuromuscular disorders (NMDs).
To implement a 3D sequence for quantifying simultaneously fat fraction (FF) and water T (T ) in the skeletal muscle, evaluate regular undersampling in the partition-encoding direction, and compare it to a recently proposed 2D MR fingerprinting sequence with water and fat separation (MRF T -FF).
Prospective.
PHANTOM/SUBJECTS: Seventeen-vial phantom at different FF and T , 11 healthy volunteers, and 6 subjects with different NMDs.
FIELD STRENGTH/SEQUENCE: 3T/3D MRF T -FF, 2D MRF T -FF, STEAM MRS ASSESSMENT: FF and T measured with the 2D and 3D sequences were compared in the phantom and in vivo at different undersampling factors (US). Data were acquired in healthy subjects before and after plantar dorsiflexions and at rest in patients.
Linear correlations, Bland-Altman analysis, two-way repeated measures analysis of variance (ANOVA), Student's t-test.
Up to a US factor of 3, the undersampled acquisitions were in good agreement with the fully sampled sequence (R ≥ 0.98, T bias ≤10 msec, FF bias ≤4 × 10 ) both in phantom and in vivo. The 2D and 3D MRF T -FF sequences provided comparable T and FF values (R ≥ 0.95, absolute T bias ≤35 msec, and absolute FF bias ≤0.003). The plantar dorsiflexion induced a significant increase of T in the tibialis anterior and extensor digitorum (relative increase of +10.8 ± 1.7% and + 7.7 ± 1.4%, respectively, P < 0.05), that was accompanied by a significant reduction of FF in the tibialis anterior (relative decrease of -16.3 ± 4.0%, P < 0.05). Some subjects with NMDs presented increased and heterogeneous T and FF values throughout the leg.
Quantitative 3D T and FF maps covering the entire leg were obtained within acquisition times compatible with clinical research (4 minutes 20 seconds) and a 1 × 1 × 5 mm spatial resolution.
2 TECHNICAL EFFICACY: Stage 2.
定量肌肉 MRI 是一种强大的工具，可用于监测神经肌肉疾病（NMD）患者的肌肉内脂肪替代和疾病活动。
实现一种用于同时量化骨骼肌中脂肪分数（FF）和水 T（T）的 3D 序列，评估在分区编码方向上的常规欠采样，并将其与最近提出的具有水和脂肪分离（MRF T-FF）的 2D MR 指纹图谱序列进行比较。
前瞻性。
体模/受试者：在不同 FF 和 T 的 17 管体模中，11 名健康志愿者和 6 名患有不同 NMD 的受试者。
磁场强度/序列：3T/3D MRF T-FF、2D MRF T-FF、STEAM MRS
在体模和不同欠采样因子（US）下，比较 2D 和 3D 序列测量的 FF 和 T。在健康受试者中，在进行足底背屈和休息前后采集数据，在患者中仅在休息时采集数据。
线性相关性、Bland-Altman 分析、双向重复测量方差分析（ANOVA）、学生 t 检验。
在 US 因子高达 3 的情况下，在体模和体内，欠采样采集与完全采样序列具有良好的一致性（R≥0.98，T 偏差≤10 msec，FF 偏差≤4×10）。2D 和 3D MRF T-FF 序列提供了可比的 T 和 FF 值（R≥0.95，绝对 T 偏差≤35 msec，绝对 FF 偏差≤0.003）。足底背屈引起胫骨前肌和趾伸肌 T 的显著增加（相对增加分别为+10.8±1.7%和+7.7±1.4%，P<0.05），同时胫骨前肌的 FF 显著减少（相对减少-16.3±4.0%，P<0.05）。一些患有 NMD 的受试者在整个腿部呈现出增加的和不均匀的 T 和 FF 值。
在与临床研究兼容的采集时间（4 分 20 秒）内获得了覆盖整个腿部的定量 3D T 和 FF 图，空间分辨率为 1×1×5mm。
2 技术功效：2 级。
