磁共振弥散张量成像对脊髓损伤的临床应用价值

磁共振弥散张量成像对脊髓损伤的临床

应用价值

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作者：陈蕾，刘国利，王大维，陈延杰

【摘要】目的：探讨磁共振弥散张量成像(diffusion tensor imaging, DTI)对脊髓损伤的临床应用价值。方法：选择42例健康志愿者作为对照组和54例脊髓型颈椎病作为病例组进行颈椎常规磁共振成像(MRI)及DTI，分别测量各组表观弥散系数(apparent diffusion coefficient, ADC)、部分各项异性(fractional anisotropy, FA)值，并显示其弥散张量纤维束(diffusion tensor tracking, DTT)。结果：对照组的平均ADC值为(830.34±215.86)×106 mm2/s，平均FA值为(536.03±40.00)×103。脊髓慢性损伤患者平均ADC值为(1107.60±47.55)×106 mm2/s，较对照组升高，有统计学意义(P0.01)，平均FA值为(425.91±59.48)×103，较对照组下降，有统计学意义(P0.01)。结论：DTI较常规MRI成像能更早显示脊髓的损伤，ADC值、FA值及DTT图是检测早期脊髓损伤微观结构的敏感指标。

【关键词】磁共振;弥散张量成像;脊髓损伤

Clinical application of magnetic resonance diffusion tensor imaging for spinal cord injury diagnosisCHEN Lei1, LIU Guo li2, WANG Da wei2, CHEN Yan jie2(1. Interventional Radiology Department,Longgang Central Hospital of Shenzhen, Shenzhen 518116;2.Department of Radiology, Changchun Communicable Disease Hospital, Changchun 130123, China)[ABSTRACT] Objective: To investigate the clinical application of magnetic resonance (MR) diffusion tensor imaging for spinal cord injury diagnosis. Methods: Conventional cervical magnetic resonance imaging (MRI) scanning and MR diffusion tensor imaging were performed on 54 patients with cervical spondylotic myelopathy and 42 cases of healthy volunteers as a healthy control group. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured, diffusion tensor tracking (DTT) was showed in each group. Results: The average ADC value is(830.34±215.86)×106 mm2/s, the average FA value is (536.03±40.00) ×10 3 in control group; in contrast the average ADC value is(1 107.60±47.55)×106 mm2/s,higher than the control group with statistical significant difference(P0.01), and the average FA value is (425.91 ±59.48)×10 3 , lower than the control group with statistical significant difference(P0.01). Conclusion: MR diffusion tensor imaging can show the injury in the spinal

cord at earlier stage. ADC value, FA value and DTT are sensitive indicators of the early detection of micro structure of spinal cord injury.

[KEY WORDS] MR; Diffusion tensor imaging; Spinal cord injury

脊髓损伤的发病率为(20～40)/100万，早期检测脊髓损伤及其程度，了解轴突损伤再生及再髓鞘化过程，对于脊髓损伤治疗及预后具有重要意义。常规磁共振成像(MRI)检查结果低估了脊髓损伤的程度[1]，不能准确评估脊髓的功能状态。目前有关脊髓评价和治疗效果验证主要依靠临床的主观评价，其评价缺乏客观的功能影像学标准。磁共振弥散张量成像 (diffusion tensor imaging, DTI) 技术利用多个不同方向的扩散敏感梯度对水分子的扩散方向性进行量化，已成功的应用于脑组织微观结构改变的定量分析及神经纤维束成像。DTI能够反映脊髓中的水分子扩散各向异向性的改变，从而显示脊髓的细微病理生理变化[2]。脊髓型颈椎病是中、老年人的常见病、多发病，慢性持续的压迫造成脊髓慢性受压和缺损，近期脊髓的脱髓鞘、神经元坏死和液化囊变等。本研究通过对正常人群及脊髓型颈椎病患者进行常规MRI和DTI检查，测量其表观弥散系数(ADC)、部分各项异性(FA)值，并显示其弥散张量纤维束(DTT)，通过对脊髓损伤检测敏感性、特异性、阳性预测值、阴性预测值的差异分析，探讨DTI对脊髓损伤性病变的临床应用价值。

1 资料与方法