MRI 显示杜氏肌营养不良症患者骨骼肌组织中离子动态平衡的早期变化。

Na MRI depicts early changes in ion homeostasis in skeletal muscle tissue of patients with duchenne muscular dystrophy.

机构信息

NMR Laboratory, Institute of Myology, Paris, France.

NMR laboratory, CEA/DRF/IBFJ/MIRCen, Paris, France.

出版信息

J Magn Reson Imaging. 2019 Oct;50(4):1103-1113. doi: 10.1002/jmri.26681. Epub 2019 Feb 4.

DOI:10.1002/jmri.26681

PMID:30719784

Abstract

BACKGROUND

Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disease leading to progressive muscle wasting. Since there is a need for MRI variables that serve as early sensitive indicators of response to treatment, several quantitative MRI methods have been suggested for disease monitoring.

PURPOSE

To evaluate the potential of sodium ( Na) and proton ( H) MRI methods to assess early pathological changes in skeletal muscle of DMD.

STUDY TYPE

Prospective clinical study.

POPULATION

Na and H MRI of the right leg were performed in 13 patients with DMD (age 7.8 ± 2.4) and 14 healthy boys (age 9.5 ± 2.2).

FIELD STRENGTH/SEQUENCE: 3 T including a multiecho-spin-echo sequence, diffusion-weighted sequences, H spectroscopy, 3-pt Dixon, and Na ultrashort echo time sequences.

ASSESSMENT

We obtained water T maps, fat fraction (FF), pH, and diffusion properties of the skeletal muscle tissue. Moreover, total tissue sodium concentration (TSC) was calculated from the Na sequence. Intracellular-weighted Na signal (ICwS) was derived from Na inversion-recovery imaging.

STATISTICAL TESTS

Results from DMD patients and controls were compared using Wilcoxon rank-sum tests and repeated analysis of variance (ANOVA). Spearman-rank correlations and area under the curve (AUC) were calculated to assess the performance of the different MRI methods to distinguish dystrophic from healthy muscle tissue.

RESULTS

FF, water T , and pH were higher in DMD patients (0.07 ± 0.03, 39.4 ± 0.8 msec, 7.06 ± 0.03, all P < 0.05) than in controls (0.02 ± 0.01, 36.0 ± 0.4 msec, 7.03 ± 0.02). No difference was observed in diffusion properties. TSC (26.0 ± 1.3 mM, P < 0.05) and ICwS (0.69 ± 0.05 a.u., P < 0.05) were elevated in DMD (controls: 16.5 ± 1.3 mM and 0.47 ± 0.04 a.u.). The ICwS was frequently abnormal in DMD even when water T , FF, and pH were in the normal range. Na MRI showed higher AUC values in comparison to the H methods.

DATA CONCLUSION

Sodium anomalies were regularly observed in patients with DMD compared with controls, and were present even in absence of fatty degenerative changes and water T increases.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1103-1113.

摘要

背景

杜氏肌营养不良症（DMD）是一种遗传性神经肌肉疾病，导致进行性肌肉萎缩。由于需要能够作为治疗反应早期敏感指标的 MRI 变量，因此已经提出了几种定量 MRI 方法来进行疾病监测。

目的

评估钠（Na）和质子（H）MRI 方法在评估 DMD 骨骼肌早期病理变化中的潜力。

研究类型

前瞻性临床研究。

人群

对 13 名 DMD 患者（年龄 7.8±2.4）和 14 名健康男孩（年龄 9.5±2.2）的右腿进行了 Na 和 H MRI 检查。

磁场强度/序列：3T 场强，包括多回波自旋回波序列、扩散加权序列、H 波谱、3 点 Dixon 和 Na 超短回波时间序列。

评估

我们获得了水 T 图谱、脂肪分数（FF）、pH 值和骨骼肌组织的扩散特性。此外，还从 Na 序列中计算出了总组织钠浓度（TSC）。从 Na 反转恢复成像中得出细胞内加权 Na 信号（ICwS）。

统计学检验

使用 Wilcoxon 秩和检验和重复方差分析（ANOVA）比较 DMD 患者和对照组的结果。计算 Spearman 秩相关系数和曲线下面积（AUC），以评估不同 MRI 方法在区分营养不良和健康肌肉组织方面的性能。

结果

与对照组相比（0.02±0.01、36.0±0.4msec、7.03±0.02），DMD 患者的 FF、水 T 和 pH 值更高（0.07±0.03、39.4±0.8msec、7.06±0.03，均 P<0.05）。扩散特性没有差异。DMD 患者的 TSC（26.0±1.3mM，P<0.05）和 ICwS（0.69±0.05a.u.，P<0.05）升高（对照组：16.5±1.3mM 和 0.47±0.04a.u.）。即使水 T 、FF 和 pH 值在正常范围内，DMD 患者的 ICwS 也经常异常。与 H 方法相比，Na MRI 显示出更高的 AUC 值。