Relationship of MRI to ASIA Impairment Scale in Chronic Spinal Cord Injury

描述（由申请人提供）：本研究的目的有两个：1)通过建立慢性脊髓损伤（SCI）的成像标准来增加美国脊髓损伤协会（ASIA）损伤量表的分类价值，2)使用先进的MR成像技术作为工具来了解有助于残余神经功能和恢复能力的结构变量。损伤中心保留的白质边缘是脊髓损伤病理的特征，该组织的完整性决定了保留功能的数量。高分辨率成像对于观察造成损伤中心部位和远端不同功能水平的细微结构差异是必要的。脊髓成像由于脊髓的小尺寸、周围骨骼的干扰、呼吸和心血管相关运动以及脑脊液脉动伪影而变得复杂。最近，肯尼迪克里格研究所的F.M. Kirby功能性脑成像研究中心的研究人员已经成功地使用扩散张量成像（DTI）和磁化转移（MT）对60多个受伤的脊髓进行了可视化。这些成像技术具有足够的分辨率和质量，可以将DTI和mt衍生的对白质破坏敏感的指标与慢性脊髓损伤的神经功能联系起来。我们通过通道特异性dti衍生的指标，如分数各向异性（FA）、平均扩散系数（MD）、平行和垂直特征值（；||和；4）和MTCSF（经脑脊液归一化的磁化转移加权图像），而不是传统的T1和T2加权成像，解决了通过ASIA标准临床上定义的神经功能/缺陷与慢性脊髓损伤患者白质通路紊乱有关的特定假设。120名患者被分为四个ASIA级别（ASIA A-C和E），将使用常规（T1, T2）和先进（DTI， MT） MRI技术进行成像。在这些受试者中，病变中心部位和远端白质的完整性将使用DTI和MT以一种特定的方式进行定义，并将测试与ASIA临床分类、神经运动和感觉测试（Aim1）以及定量振动阈值感觉测试（Aim2）的关系。公共卫生相关性：众所周知，损伤后脊髓功能的残余量与损伤后白质的组成和健康状况有关，但目前尚不清楚白质束的保存程度对神经功能是必要的。开发高分辨率、无创成像方法来确定损伤后白质的完整性，对于设计和测试脊髓损伤患者的恢复性治疗非常重要。我们建议应用最近改进的先进磁共振成像（MRI）方法来量化脊髓白质完整性，并将获得的信息与美国脊柱损伤协会（ASIA）损伤量表评估的运动和感觉功能评分联系起来。

DESCRIPTION (provided by applicant): The objective of this investigation is two-fold: 1) to add to the classification value of the American Spinal Injury Association (ASIA) Impairment Scale by establishing imaging criteria for chronic spinal cord injury (SCI), 2) to use advanced MR imaging techniques as tools to understand the structural variables that contribute to residual neurological function and the capacity for recovery. A preserved rim of white matter at the injury epicenter characterizes SCI pathology, and the integrity of this tissue determines the amount of preserved function. High resolution imaging is necessary to visualize the subtle structural differences that are responsible for differing levels of function both at the site of and distal to the injury epicenter. Spinal cord imaging is complicated by the small size of the cord, interference from surrounding bone, respiratory and cardiovascular related motion and cerebrospinal fluid pulsation artifacts. Recently, investigators at the F.M. Kirby Research Center for Functional Brain Imaging at Kennedy Krieger Institute have successfully used Diffusion Tensor Imaging (DTI) and Magnetization Transfer (MT) to visualize over sixty injured spinal cords. These imaging techniques are of sufficient resolution and quality to correlate DTI- and MT-derived metrics sensitive to white matter disruption with neurological function in chronic SCI. We address the specific hypothesis that neurological function/deficit clinically defined through the ASIA criteria is related to disordered white matter pathways in persons with chronic SCI through tract specific DTI-derived metrics such as: fractional anisotropy (FA), average diffusion coefficient (MD), parallel and perpendicular eigenvalues (;|| and ;4) and MTCSF (magnetization transfer weighted image normalized by cerebrospinal fluid), but not conventional T1- and T2- weighted imaging. One hundred and twenty individuals divided amongst four ASIA classes (ASIA A-C and E) will be imaged using conventional (T1, T2) and advanced (DTI, MT) MRI techniques. The integrity of white matter both at the site of and distal to the epicenter of the lesion in these subjects will be defined in a tract specific manner using DTI and MT and will be tested for relationships to ASIA clinical classification and neurological motor and sensory testing (Aim1) and to quantitative vibration threshold sensory testing (Aim2). PUBLIC HEALTH RELEVANCE: It is known that the amount of residual spinal cord function after injury is related to the composition and health of the white matter that remains at the level of injury, but currently it is not known exactly how much preservation of the white matter tracts is necessary for neurological function. Development of high resolution, non-invasive imaging methods to determine the integrity of white matter after injury is important for designing and testing restorative treatments for individuals living with SCI. We propose to apply recently improved advanced magnetic resonance imaging (MRI) methods to quantify white matter integrity in the spinal cord and relate the information obtained to the motor and sensory function scores assessed by the American Spine Injury Association (ASIA) Impairment Scale.