脊髓型颈椎病MRI T2信号比值变化与临床表现及预后的关系

目的 将MRI T2WI信号量化分类,同时探讨其与术前临床表现、预后三者之间的关系.方法 2005年4月至2007年7月共计73例患者,均行前路、后路或后前路联合手术.术前所有患者均行高分辨率1.5T MRI成像.于矢状面T2WI脊髓受压信号增高最明显部位计算机测量信号强度值,取兴趣区面积为0.05 cm2,再于颈7胸1椎体水平脊髓信号正常部位测量信号强度值,取兴趣区面积为0.3 cm2,计算得出两者比值(0.05 cm2面积信号强度值/0.3 cm2面积信号强度值).如T2 WI脊髓信号无明显改变,则取脊髓受压最严重部位0.05 cm2为兴趣区测量信号强度值.比值数据经对数转换、系统聚类后分为3组.结合临床表现分析相互之间的关系.结果 各组间改善率、年龄、术前JOA评分经方差分析F值、P值分别为F=22.009、P<0.001,F=6.371、P=0.003,F=5.561、P=0.006.此3项指标各组之间差异有统计学意义.各组间Babinski征及性别经卡方检验χ2值及P值分别为χ2=15.719、P<0.001,χ2=1.898、P=0.387,Babinski征各组之间差异有统计学意义,性别差异在组间无统计学意义.各组间信号比值对数、术后JOA评分及病程经秩和检验3项指标各组之间差异均有统计学意义,χ2值及P值分别为χ2=62.616、P<0.001,χ2=25.946、P<0.001,χ2=13.952、P=0.001.结论 低信号比值组即无明显T2WI高信号和轻度存在T2WI高信号患者,往往年龄相对较小,病程相对较短,减压术后效果较好.反之如果T2WI高信号逐步增高且伴随锥体束征出现,则提示预后较前者欠佳.

Relation of MR T2 image signal intensity ratio of cervical spondylotic myelopathy with clinical manifestations and prognosis

Objective To investigate whether the signal intensity ratio in magnetic resonance imaging (MRI) and clinical manifestations can reflect prognosis in patients with cervical compressive myelopathy. Methods Seventy-three patients with cervical compressive myelopathy treated with anterior, posterior, or posterior-anterior united decompression underwent 1.5-T MRI before surgery. T2-weighted images (T2WI) of the sagittal signal intensity on the cervical severe compression cord were obtained, and the regions of interest (ROIs) were taken by 0.05 cm2. T2-weighted MR images of sagittal normal cord signal on the cervical between C7-T1 disc levels were obtained, and the ROIs were taken by 0.3 cm2. Signal value is measured by computer and the signal ratio between the regions of the 0.05 cm2 and 0.3 cm2 was calculated. If no intramedullary high signal intensity was noted on T2-weighted MR images, the ROIs were taken by 0.05 cm2 of the severe compression cord. The 73 patients were divided into 3 groups:low, medium, and high signal ratio groups (Group 1, 2, and 3, n = 18, 32, and 23 respectively). Results The recovery rate and JOA score of Group 1 were significantly higher, the age and Babinaki sign positive rate were significantly lower, and disease duration was shorter in Group 1 than in Groups 2 and 3 (F=22.009, P < 0.001 ,F = 5.561,P=0.006,F=6.371,P=0.003,χ2 = 15.719,P<0.001, and χ2=13.952,P=0.001). There was no significant differences in sex among these 3 groups (χ2=1. 898,P=0.387). Conclusion The patients with light or without intramedullary signal change on T2WI experience a good surgical outcome. However, the patients with increase of signal intensity ratio and the occurrence of pyramidal sign show a poor prognosis after surgery.