From Radiology and Imaging Sciences (C.-Y.L., J.Y., W.C.K., R.M.S.) and Rehabilitation Medicine Department (J.A.S., G.J.), Clinical Center, National Institute of Diabetes and Digestive and Kidney Diseases (R.O.), Neurogenetics Branch, National Institute of Neurological Disorders and Stroke (A.K.M.), and Medical Genetics Branch, National Human Genome Research Institute (W.A.G., N.C.), NIH, Bethesda, MD.
Neurology. 2021 Feb 2;96(5):e798-e808. doi: 10.1212/WNL.0000000000011231. Epub 2020 Nov 20.
To characterize muscle involvement and evaluate disease severity in patients with GNE myopathy using skeletal muscle MRI and proton magnetic resonance spectroscopy (H-MRS).
Skeletal muscle imaging of the lower extremities was performed in 31 patients with genetically confirmed GNE myopathy, including T1-weighted and short tau inversion recovery (STIR) images, T1 and T2 mapping, and H-MRS. Measures evaluated included longitudinal relaxation time (T1), transverse relaxation time (T2), and H-MRS fat fraction (FF). Thigh muscle volume was correlated with relevant measures of strength, function, and patient-reported outcomes.
The cohort was representative of a wide range of disease progression. Contractile thigh muscle volume ranged from 5.51% to 62.95% and correlated with thigh strength ( = 0.91), the 6-minute walk test ( = 0.82), the adult myopathy assessment tool ( = 0.83), the activities-specific balance confidence scale ( = 0.65), and the inclusion body myositis functional rating scale ( = 0.62). Four stages of muscle involvement were distinguished by qualitative (T1W and STIR images) and quantitative methods: stage I: unaffected muscle (T1 = 1,033 ± 74.2 ms, T2 = 40.0 ± 1.9 ms, FF = 7.4 ± 3.5%); stage II: STIR hyperintense muscle with minimal or no fat infiltration (T1 = 1,305 ± 147 ms, T2 = 50.2 ± 3.5 ms, FF = 27.6 ± 12.7%); stage III: fat infiltration and STIR hyperintensity (T1 = 1,209 ± 348 ms, T2 = 73.3 ± 12.6 ms, FF = 57.5 ± 10.6%); and stage IV: complete fat replacement (T1 = 318 ± 39.9 ms, T2 = 114 ± 21.2 ms, FF = 85.6 ± 4.2%). H-MRS showed a significant decrease in intramyocellular lipid and trimethylamines between stage I and II, suggesting altered muscle metabolism at early stages.
MRI biomarkers can monitor muscle involvement and determine disease severity noninvasively in patients with GNE myopathy.
NCT01417533.
使用骨骼肌 MRI 和质子磁共振波谱（H-MRS）来描述 GNE 肌病患者的肌肉受累情况并评估疾病严重程度。
对 31 名经基因证实的 GNE 肌病患者进行下肢骨骼肌成像，包括 T1 加权和短 tau 反转恢复（STIR）图像、T1 和 T2 映射以及 H-MRS。评估的指标包括纵向弛豫时间（T1）、横向弛豫时间（T2）和 H-MRS 脂肪分数（FF）。大腿肌肉体积与相关的力量、功能和患者报告的结果指标相关。
该队列代表了广泛的疾病进展范围。收缩性大腿肌肉体积范围为 5.51%至 62.95%，与大腿力量（ = 0.91）、6 分钟步行试验（ = 0.82）、成人肌病评估工具（ = 0.83）、活动特异性平衡信心量表（ = 0.65）和包涵体肌炎功能评定量表（ = 0.62）相关。通过定性（T1W 和 STIR 图像）和定量方法区分了肌肉受累的四个阶段：阶段 I：未受影响的肌肉（T1 = 1,033 ± 74.2 ms，T2 = 40.0 ± 1.9 ms，FF = 7.4 ± 3.5%）；阶段 II：STIR 高信号肌肉，仅有轻微或无脂肪浸润（T1 = 1,305 ± 147 ms，T2 = 50.2 ± 3.5 ms，FF = 27.6 ± 12.7%）；阶段 III：脂肪浸润和 STIR 高信号（T1 = 1,209 ± 348 ms，T2 = 73.3 ± 12.6 ms，FF = 57.5 ± 10.6%）；和阶段 IV：完全脂肪替代（T1 = 318 ± 39.9 ms，T2 = 114 ± 21.2 ms，FF = 85.6 ± 4.2%）。H-MRS 显示在阶段 I 和 II 之间肌内脂质和三甲胺的含量显著下降，提示在早期阶段肌肉代谢发生改变。
MRI 生物标志物可在 GNE 肌病患者中进行非侵入性监测肌肉受累情况并确定疾病严重程度。
NCT01417533。
