Department of Radiology, Samsung Medical Center, School of Medicine, Sungkyunkwan University, 81 Ilwon-Ro, Gangnam-gu, Seoul, 135-710, South Korea.
Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea.
Eur Radiol. 2019 Jun;29(6):3241-3252. doi: 10.1007/s00330-018-5958-1. Epub 2019 Jan 11.
This study aimed to evaluate whether diffusion tensor imaging (DTI) parameters and cross-sectional area (CSA) can differentiate between the sciatic nerve of Charcot-Marie-Tooth (CMT) disease type I (demyelinating form) patients and that of controls.
This prospective comparison study included 18 CMT type I patients and 18 age/sex-matched volunteers. Magnetic resonance imaging including DTI and axial T2-weighted Dixon sequence was performed for each subject. Region of interest analysis was independently performed by two radiologists on each side of the sciatic nerve at four levels: hamstring tendon origin (level 1), lesser trochanter of the femur (level 2), gluteus maximus tendon insertion (level 3), and mid-femur (level 4). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated. The CSA of the sciatic nerve bundle was measured using axial water-only image at each level. Comparisons of DTI parameters between the two groups were performed using the two-sample t test and Mann-Whitney U test. Interobserver agreement analysis was also conducted.
Interobserver agreement was excellent for all DTI parameter analyses. FA was significantly lower at all four levels in CMT patients than controls. RD, MD, and CSA were significantly higher at all four levels in CMT patients. AD was significantly higher at level 2 in CMT patients.
DTI assessment of the sciatic nerve is reproducible and can discriminate the demyelinating nerve pathology of CMT type I patients from normal nerves. The CSA of the sciatic nerve is also a potential parameter for diagnosing nerve abnormality in CMT type I patients.
• Diffusion tensor imaging parameters of the sciatic nerve at proximal to mid-femur level revealed significant differences between the Charcot-Marie-Tooth disease patients and controls. • The cross-sectional area of the sciatic nerve was significantly larger in the Charcot-Marie-Tooth disease patients. • Interobserver agreement was excellent (intraclass coefficient > 0.8) for all diffusion tensor imaging parameter analyses.
本研究旨在评估弥散张量成像（DTI）参数和截面积（CSA）是否可区分 Charcot-Marie-Tooth（CMT）病 1 型（脱髓鞘型）患者和对照组的坐骨神经。
这是一项前瞻性对比研究，纳入 18 例 CMT 1 型患者和 18 名年龄和性别匹配的志愿者。每位受试者均进行磁共振成像检查，包括 DTI 和轴向 T2 加权 Dixon 序列。两名放射科医生在坐骨神经的四个水平（腘绳肌腱起点[水平 1]、股骨小转子[水平 2]、臀大肌肌腱止点[水平 3]和股骨中段[水平 4]）上对每侧坐骨神经进行独立的感兴趣区分析。计算各向异性分数（FA）、平均弥散度（MD）、轴向弥散度（AD）和径向弥散度（RD）。在每个水平上使用轴向纯水图像测量坐骨神经束的 CSA。采用两样本 t 检验和 Mann-Whitney U 检验比较两组间 DTI 参数的差异。还进行了观察者间一致性分析。
所有 DTI 参数分析的观察者间一致性均为极好。与对照组相比，CMT 患者的所有四个水平的 FA 均显著降低。CMT 患者的所有四个水平的 RD、MD 和 CSA 均显著升高，CMT 患者的水平 2 的 AD 显著升高。
坐骨神经 DTI 评估具有可重复性，可区分 CMT 1 型患者的脱髓鞘神经病变与正常神经。坐骨神经 CSA 也是诊断 CMT 1 型患者神经异常的潜在参数。
股骨近端至中段水平的坐骨神经弥散张量成像参数在 CMT 患者和对照组之间存在显著差异。
CMT 患者的坐骨神经 CSA 显著增大。
所有弥散张量成像参数分析的观察者间一致性均极好（组内相关系数>0.8）。
