RELATIONSHIP BETWEEN INTRASPINAL SIGNAL AND LESION BY LINE SCAN DIFFUSION

1.本研究的目的是分析表观扩散系数（ADC）和各向异性分数（FA）在早期发现颈椎病患者脊髓异常的可行性。正常脊髓的ADC值在C2-3段为0.81 ± 0.03mm ~ 2/msec，在C4-7段为0.75 ± 0.06mm ~ 2/msec。正常脊髓的FA在C2-3水平为0.70 ± 0.05，在C4-7水平为0.66 ± 0.05。在这54%的颈椎病患者中，ADC值升高的患者在异常脊髓中显示FA值降低。用3特斯拉MRI机使用EPI扩散加权成像获得了类似的结果。但EPI图像易受磁敏感伪影和运动伪影的影响，使ADC和Famore的测量较线阵扫描图像困难。此外，当测量异常脊髓信号时，需要考虑年龄因素。ADC值与年龄呈正相关（斯皮尔曼相关，r=0.242），FA值与年龄呈负相关（斯皮尔曼相关，r=-0.244）。而ADC值和Fachang值随年龄的变化最小，颈椎病的弥散信号变化相对较大.弥散加权图像处理后的纤维束成像便于直观评价颈椎病患者脊髓受压情况.扩散加权成像和ADC/FA值被认为是有用的早期发现脊髓病变的颈椎病。它有很大的潜力作为手术标准和早期发现的指征，以服务于更好的预后疾病的额外信息。

1. The aim of the study was to analyze feasibility of Apparent Diffusion Coefficient (ADC) and Fractional Anisotropy (FA) in early detection of abnormal spinal cord in cervical spondylosis patients. ADC of the normal spinal cord was 0.81+/-0.03mm2/msec at C2-3 level and 0.75+/-0.06mm2/msec at C4-7 level In spondylosis spinal cord, ADC was elevated compared with normal spinal cord in 54% of all patients. FA of the normal spinal cord was 0.70+/-0.05 at C2-3 level and 0.66+/-0.05 at C4-7 level. In those 54% of spondylosis patients whom had elevated ADC showed reduced FA in the abnormal spinal cord. Similar result was obtained with 3 tesla MRI machine using EPI diffusion weighted imaging. Howeveg EPI images tended to be affected by susceptibility artifact and motion artifact, which made measurement of ADC and Famore difficult than measurement on Line scan images. Moreover, there is an age factor to be considered when abnormal spinal cord signals are measured. With age, ADC showed positive correlation(Spearman Correlation, r=0.242)and FA showed negative correlation (Spearman Correlation, r=-0.244). Howevee ADC and Fachanges with age are minimum and the diffusion signal changes in cervical spondylosis seemed to be relatively large.2. Tractography processed from diffusion weighted image data was convenient to visually evaluate compression of spinal cord in cervical spondylosis cases.3. Diffusion weighted images and ADC/FA values were considered to be useful for early detection of spinal cord changes in cervical spondylosis. It has a great potential as additional information for operative criteria and indication of early detection to serve better prognosis in the disease.