Beijing Jishuitan Hospital, Capital Medical University, Beijing, China.
Spine Department, Beijing Jishuitan Hospital, Capital Medical University, Beijing, China.
Eur Spine J. 2024 Mar;33(3):1230-1244. doi: 10.1007/s00586-023-08111-7. Epub 2024 Jan 29.
PURPOSE: This study aimed to investigate the effectiveness of tract-specific diffusion tensor imaging (DTI) metrics in identifying the responsible segments for neurological dysfunction in cervical spondylotic myelopathy (CSM). METHODS: The study encompassed nineteen participants diagnosed with CSM, including 10 males and 9 females. Additionally, a control group consisting of ten healthy caregivers (5 males and 5 females) were recruited with no symptoms and no compressions on magnetic resonance imaging (MRI). All participants underwent a comprehensive physical examination, MRI assessment, and DTI examination conducted by a senior chief physician. Several parameters were collected from the MR images, including the aspect ratio (defined as the anteroposterior diameter / the transverse diameter of the corresponding segment's spinal cord), transverse ratio (defined as the transverse diameter of the corresponding segment's spinal cord / the transverse diameter of the spinal cord at C2/3), and T2 high signal of the spinal cord. Furthermore, quantitative DTI metrics, such as axial diffusivity (AD), mean diffusivity (MD), radial diffusivity (RD), and fractional anisotropy (FA), were calculated using automatic region-of-interest (ROI) analysis for both whole spinal cord column and dorsal column. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic efficacy of the aspect ratio, transverse ratio, and DTI parameters. The area under the curve (AUC), sensitivity, and specificity were calculated. Intraoperative spinal cord electrophysiological examination was performed as the objective measure of spinal cord function during surgery. RESULTS: As determined by electrophysiological examination, neurological dysfunction was found in 2 patients due to C3/4 compression, in 10 patients due to C4/5 compression, in 6 patients due to C5/6 compression, and in 1 patient due to C6/7 compression. The modified Japanese Orthopedic Association scale (mJOA) was 12.71 ± 1.55 in the CSM group, with 4.87 ± 0.72 for sensory nerve function and 5.05 ± 1.35 for motor nerve function. For the control group, none of the volunteers had neurological dysfunction. T2 high signal was found at the most stenotic segment in 13 patients of the CSM group. Considering all the cervical segments, the aspect ratio (AUC = 0.823, P = 0.001, Sensitivity = 68.42%, Specificity = 82.47%) was more capable of determining the responsible segment than transverse ratio (AUC = 0.661, P = 0.027, Sensitivity = 68.42%, Specificity = 67.01%). AD, MD, and RD were significantly higher while FA was significantly lower in the responsible segment than in the irresponsible segment (P < 0.05). The AUC of DTI-Dorsal column parameters (AD, MD, RD, FA) was larger than the corresponding parameters of the DTI (Whole spinal cord). AD of DTI-Dorsal Column possessed the greatest efficacy (AUC = 0.823, sensitivity = 84.21%, specificity = 77.32%) to determine the responsible segment, larger than AD of DTI-Whole spinal cord (AUC = 0.822, P = 0.001, Sensitivity = 89.47%, Specificity = 77.32%), aspect ratio (AUC = 0.823, P = 0.001, Sensitivity = 68.42%, Specificity = 82.47%) and transverse ratio (AUC = 0.661, P = 0.027, Sensitivity = 68.42%, Specificity = 67.01%). Subgroup analysis revealed that the diagnostic efficacy of DTI and MRI parameters was influenced by cervical spine segment. CONCLUSIONS: When considering all cervical segments, AD from the DTI-Dorsal Column exhibited the most significant potential in identifying responsible segments. This potential was found to be superior to that of DTI-Whole spinal cord, aspect ratio, the most stenotic segment, T2 high signals, transverse ratio, motor nerve dysfunction, and sensory nerve dysfunction. The diagnostic effectiveness of both DTI and MRI parameters was notably influenced by the specific cervical spine segment.
目的:本研究旨在探讨特定于脊髓的弥散张量成像(DTI)指标在识别颈椎脊髓病(CSM)患者神经功能障碍责任节段中的有效性。
方法:研究纳入了 19 名 CSM 患者,包括 10 名男性和 9 名女性。此外,还招募了 10 名健康护理人员作为对照组,这些护理人员无任何症状,且 MRI 检查无任何压迫。所有参与者均接受了全面的体格检查、MRI 评估和由资深主任医师进行的 DTI 检查。从 MR 图像中收集了几个参数,包括矢状比(定义为相应节段脊髓的前后直径/横径)、横径比(定义为相应节段脊髓的横径/ C2/3 脊髓的横径)和脊髓 T2 高信号。此外,还使用自动感兴趣区(ROI)分析计算了定量 DTI 指标,如轴扩散系数(AD)、平均扩散系数(MD)、径向扩散系数(RD)和各向异性分数(FA),用于整个脊髓柱和背柱。构建了受试者工作特征(ROC)曲线来评估矢状比、横径比和 DTI 参数的诊断效能。计算了曲线下面积(AUC)、敏感度和特异度。术中脊髓电生理检查作为手术期间脊髓功能的客观测量指标。
结果:通过电生理检查发现,2 例患者因 C3/4 受压导致神经功能障碍,10 例患者因 C4/5 受压导致神经功能障碍,6 例患者因 C5/6 受压导致神经功能障碍,1 例患者因 C6/7 受压导致神经功能障碍。CSM 组改良日本矫形协会量表(mJOA)评分为 12.71±1.55,感觉神经功能评分为 4.87±0.72,运动神经功能评分为 5.05±1.35。对照组的志愿者均无神经功能障碍。在 CSM 组的 13 例患者中,最狭窄节段发现 T2 高信号。考虑到所有颈椎节段,矢状比(AUC=0.823,P=0.001,敏感度=68.42%,特异性=82.47%)比横径比(AUC=0.661,P=0.027,敏感度=68.42%,特异性=67.01%)更能确定责任节段。在责任节段,AD、MD 和 RD 显著升高,FA 显著降低(P<0.05)。DTI-Dorsal Column 各参数(AD、MD、RD、FA)的 AUC 大于 DTI(整个脊髓)的相应参数。DTI-Dorsal Column 的 AD 对确定责任节段的效能最大(AUC=0.823,敏感度=84.21%,特异性=77.32%),大于 DTI-Whole spinal cord 的 AD(AUC=0.822,P=0.001,敏感度=89.47%,特异性=77.32%)、矢状比(AUC=0.823,P=0.001,敏感度=68.42%,特异性=82.47%)和横径比(AUC=0.661,P=0.027,敏感度=68.42%,特异性=67.01%)。亚组分析表明,DTI 和 MRI 各参数的诊断效能受颈椎节段的影响。
结论:当考虑所有颈椎节段时,DTI-Dorsal Column 的 AD 具有确定责任节段的最大潜力。其效能优于 DTI-Whole spinal cord、矢状比、最狭窄节段、T2 高信号、横径比、运动神经功能障碍和感觉神经功能障碍。DTI 和 MRI 各参数的诊断效能均受特定颈椎节段的显著影响。