PREDICTIVE VALUE OF DIFFUSION MRI IN CERVICAL SPONDYLOTIC MYELOPATHY

项目摘要 退行性脊髓型颈椎病(CSM)是引起脊髓损伤(SCI)的最常见原因 这是一个重大的公共卫生问题。限制改善治疗努力的一个主要缺点 CSM患者的一个问题是缺乏可作为临床决策基础的可量化指标。高级核磁共振 扩散张量成像(DTI)等技术在这一领域显示出了良好的前景。DTI测量 组织中水置换的大小、各向异性和方向性，并提供可量化的测量 沿白质束的定向扩散率。虽然DTI为评估脑白质提供了一个有价值的工具 完整性，不幸的是，我们发现目前的DTI技术是有缺陷的，因为扩散属性源于 随着病理和解剖复杂性的增加，使用DTI失去了特异性和敏感性。因此， 使用DTI对长期结果的预测仍然不确定。为了克服影响DTI分析的因素， 我们开发了扩散基础光谱成像(DBSI)，以更准确地描绘脑白质损伤， 允许区分和量化环境中的轴突损伤/丢失、脱髓鞘和炎症 脊髓受压的症状。DBSI除了量化轴突/髓鞘损伤外，还可以量化水肿/组织丢失，提供 改进的成像生物标记物可以更准确地预测患者的临床病程、治疗反应和 远期预后。该提案的长期目标是建立和验证非侵入性成像 预测手术减压后临床病程和治疗反应的生物标志物 脊髓型颈椎病患者。第一个目标是评估脊髓DBSI病理指标是否反映了神经学 脊柱减压术后患者的神经功能损害及远期预后预测 与CSM合作。这一目标将检验这样一种假设，即轻度脊髓型颈椎病的脊髓压迫的临床表现 主要是水肿和炎症的反映，真正的轴突丢失的发生率较低； 相比之下，在中度CSM患者中观察到的功能恢复的高度变异性可归因于 脊髓受压导致永久性轴突丧失的风险更大。这项提议的第二个目的是， 将改进DBSI模型，以评估血流不足对脊髓病理的影响并改进 脊髓型颈椎病轴突丢失量化的准确性。这一目标将检验以下假设：脊髓的作用 可通过在DBSI中包括体素内非相干运动(IVIM)来评估CSM病理中的血流 建模：DBSI导出的轴突体积的准确性可以通过包括轴突内扩散来提高 DBSI建模中的组件。 这种非侵入性DBSI生物标志物的识别和验证将为临床提供指导 管理、长期预后和家庭咨询。一种非侵入性生物标志物在临床中的应用 预测脊髓型颈椎病手术治疗中的功能恢复将代表一种新的和 脊髓型颈椎病的治疗取得实质性进展。

Project Abstract Degenerative cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord injury (SCI) representing a significant public health problem. A major shortcoming limiting efforts to improve the treatment of patients with CSM is the lack of quantifiable metrics on which to base clinical decisions. Advanced MRI techniques, such as diffusion tensor imaging (DTI) have shown promise in this area. DTI measures the magnitude, anisotropy, and directionality of water displacement in tissue and provides quantifiable measures of directional diffusivity along white matter tracts. While DTI provides a valuable tool to assess white matter integrity, unfortunately, we have found current DTI techniques are flawed because diffusion properties derived using DTI lose specificity and sensitivity with increasing pathological and anatomical complexity. Thus the prediction of long-term outcome using DTI remains uncertain. To overcome factors confounding DTI analysis, we developed diffusion basis spectrum imaging (DBSI), to more accurately delineate white matter injury, allowing differentiation and quantification of axonal injury/loss, demyelination, and inflammation in the setting of spinal cord compression. DBSI quantifies edema/tissue loss in addition to axon/myelin injury, providing improved imaging biomarkers that more accurately predict a patient's clinical course, response to therapy, and long-term prognosis. The long-term objective of this proposal is to establish and validate non-invasive imaging biomarkers that are predictors of clinical course and therapeutic response to surgical decompression in patients with CSM. The first aim will assess whether spinal cord DBSI pathological metrics reflect neurological impairments and predict long-term neurologic outcomes following decompressive spinal surgery in patients with CSM. This aim will test the hypothesis that clinical manifestations of spinal cord compression in mild CSM are predominantly a reflection of edema and inflammation, with a lower incidence of true axonal loss; In contrast the high variability of functional recovery observed in moderate CSM patients is attributable to a greater risk for permanent axonal loss caused by spinal cord compression. The second aim of this proposal, will refine DBSI modeling for assessing effects of blood flow deficits on spinal cord pathology and improving the accuracy of axonal loss quantification in CSM. This aim will test the hypothesis that the effect of spinal cord blood flow on CSM pathology may be assessed by including Intra-Voxel-Incoherent-Motion (IVIM) in DBSI modeling; the accuracy of DBSI-derived axon volume may be improved by including intra-axonal diffusion component in DBSI modeling. The identification and validation of such non-invasive DBSI biomarkers will provide guidance on clinical management, long-term prognosis, and family counseling. The validation of a non-invasive biomarker for predicting functional recovery in the surgical management of cervical myelopathy would represent a new and substantial advance in the treatment of cervical myelopathy.