Mankodi Ami, Bishop Courtney A, Auh Sungyoung, Newbould Rexford D, Fischbeck Kenneth H, Janiczek Robert L
Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
Imanova Centre for Imaging Sciences, Hammersmith Hospital, London W12 0NN, UK.
Neuromuscul Disord. 2016 Oct;26(10):650-658. doi: 10.1016/j.nmd.2016.07.013. Epub 2016 Jul 28.
The purpose of this study was to explore the use of iterative decomposition of water and fat with echo asymmetry and least-squares estimation Carr-Purcell-Meiboom-Gill (IDEAL-CPMG) to simultaneously measure skeletal muscle apparent fat fraction and water T (T) in patients with Duchenne muscular dystrophy (DMD). In twenty healthy volunteer boys and thirteen subjects with DMD, thigh muscle apparent fat fraction was measured by Dixon and IDEAL-CPMG, with the IDEAL-CPMG also providing T as a measure of muscle inflammatory activity. A subset of subjects with DMD was followed up during a 48-week clinical study. The study was in compliance with the Patient Privacy Act and approved by the Institutional Review Board. Apparent fat fraction in the thigh muscles of subjects with DMD was significantly increased compared to healthy volunteer boys (p <0.001). There was a strong correlation between Dixon and IDEAL-CPMG apparent fat fraction. Muscle T measured by IDEAL-CPMG was independent of changes in apparent fat fraction. Muscle T was higher in the biceps femoris and vastus lateralis muscles of subjects with DMD (p <0.05). There was a strong correlation (p <0.004) between apparent fat fraction in all thigh muscles and six-minute walk distance (6MWD) in subjects with DMD. IDEAL-CPMG allowed independent and simultaneous quantification of skeletal muscle fatty degeneration and disease activity in DMD. IDEAL-CPMG apparent fat fraction and T may be useful as biomarkers in clinical trials of DMD as the technique disentangles two competing biological processes.
本研究的目的是探索利用具有回波不对称性和最小二乘估计的Carr-Purcell-Meiboom-Gill迭代水脂分解法（IDEAL-CPMG），同时测量杜氏肌营养不良症（DMD）患者骨骼肌的表观脂肪分数和水T2（T2）。对20名健康志愿者男孩和13名DMD患者进行研究，通过Dixon法和IDEAL-CPMG测量大腿肌肉表观脂肪分数，IDEAL-CPMG还可提供T2作为肌肉炎症活动的指标。在一项为期48周的临床研究中，对部分DMD患者进行了随访。本研究符合《患者隐私法》，并获得了机构审查委员会的批准。与健康志愿者男孩相比，DMD患者大腿肌肉的表观脂肪分数显著增加（p <0.001）。Dixon法和IDEAL-CPMG法测得的表观脂肪分数之间存在强相关性。IDEAL-CPMG测量的肌肉T2与表观脂肪分数的变化无关。DMD患者股二头肌和股外侧肌的肌肉T2较高（p <0.05）。DMD患者所有大腿肌肉的表观脂肪分数与6分钟步行距离（6MWD）之间存在强相关性（p <0.004）。IDEAL-CPMG能够独立且同时定量DMD患者骨骼肌的脂肪变性和疾病活动。由于该技术能够区分两个相互竞争的生物学过程，IDEAL-CPMG测得的表观脂肪分数和T2可能作为DMD临床试验中的生物标志物。
