Magnetic Resonance Elastography as a Personalized Assessment of Intervertebral Disc Mechanics

项目摘要/摘要 腰背痛(LBP)是世界范围内导致残疾的主要原因，腰椎成像在 它的标准护理过程。然而，典型的临床影像只能提供对脊柱的定性评估。 《关于改善慢性下腰痛患者预后分层的新研究》被 NIH疼痛联盟特别工作组最近呼吁对慢性LBP的研究标准。 腰椎间盘(IVD)退变是LBP的主要或次要原因，其特征是进行性 组织结构和成分的分解导致机械行为和内部结构的改变 可以为神经内长提供手段的破坏，这是间盘源性疼痛的前兆。磁共振 弹性成像(Mre)是一种非侵入性的成像技术，它跟踪传播的应变波。 通过软组织并允许在活体内测量组织材料属性。支持数据 表明MRE衍生的剪切刚度可以作为对这种疾病过程敏感的生物标记物。 与非操作的对照相比，可以检测到操作的IVD中的内部中断。然而，改进的MRE 扫描序列以减少扫描时间，机械验证MRE导出的粘弹性特性，以及 在临床使用之前，需要确定MRE检测到的内部干扰的限度。 这项研究的长期目标是提供一种安全和非侵入性的方法来量化机械 脊柱内肌肉骨骼软组织的功能，允许早期诊断损伤和疾病，改善 患者分层，便于对LBP的恢复性干预进行体内评估。目标1开发了一种定制 自旋回波平面成像MRE序列可减少扫描次数，同时提高信噪比。目标 2验证了健康和退变的IVD组织的MRE衍生的粘弹性材料特性 材料测试，并确定MRE可以检测到的类型、方向和最小缺陷尺寸 身体组织。目标3确定材料性能和内部缺陷的MRE测量结果 结合磁共振测量组织成分的空间变异可以区分疼痛和非疼痛 分别来自无症状受试者和与椎间盘相关的慢性LBP患者的疼痛IVD。这项工作将 在更短的时间内改进数据收集，这适用于所有MRE应用，并允许体内 粘弹性机械性能和内部损伤的评估。IVD的无创性体内评价 机械功能可能允许LBP患者的预后分层，并作为一种新的“患者特异性” 识别损害并量化疾病和治疗的功能后果的临床工具。

Project Summary / Abstract Low back pain (LBP) is the leading cause of disability worldwide and lumbar imaging has become ubiquitous in its standard course of care. However, typical clinical imaging offers only a qualitative assessment of spine anatomy and “new research to improve prognostic stratification of patients with chronic low back pain” was recently called for by the NIH Pain Consortium Task Force on Research Standards for Chronic LBP. Intervertebral disc (IVD) degeneration, a primary or secondary cause of LBP, is characterized by the progressive breakdown of the tissue's structure and composition resulting in altered mechanical behaviors and internal disruptions that can provide a means for nerve ingrowth, a precursor for discogenic pain. Magnetic resonance elastography (MRE) is a non-invasive imaging technique that tracks propagating strain waves as they move through soft tissues and allows the measurement of tissue material properties in-vivo. Supporting data demonstrates that MRE-derived shear stiffness can serve as a biomarker sensitive to this disease process and can detect internal disruptions within operated IVDs compared to non-operated controls. Yet, improved MRE scan sequences to reduce scan time, mechanical validation of MRE-derived viscoelastic properties, and determination of the limits of MRE-detected internal disruptions are required prior to clinical utilization. The long-term goal of this research is to provide a safe and non-invasive method to quantify the mechanical function of musculoskeletal soft-tissues within the spine to allow early diagnosis of injury and disease, improve patient stratification and facilitate in-vivo evaluation of restorative interventions for LBP. Aim 1 develops a custom spin-echo echo-planar imaging MRE sequence to reduce scan times while simultaneously increasing SNR. Aim 2 validates the MRE-derived viscoelastic material properties of healthy and degenerated IVD tissue against material testing and also determines the type, orientation and minimum defect size that MRE can detect in cadaveric tissue. Aim 3 determines if MRE-derived measurements of material properties and internal defects together with MR measurements of spatial variations in tissue composition can differentiate a painful and non- painful IVD from asymptomatic subjects and disc-related chronic LBP patients, respectively. This work will improve data collection in a reduced time, which is applicable to all MRE applications, and allow in-vivo assessment of viscoelastic mechanical properties and internal damage. Non-invasive in-vivo assessment of IVD mechanical function may allow the prognostic stratification of LBP patients and serve as a novel “patient specific” clinical tool to identify damage and quantify the functional consequences of disease and treatment.