NON-INVASIVE MEASUREMENT OF INTERVERTEBRAL DISC OSMOTIC PRESSURE WITH T1P MRI

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 椎间盘退变是一种常见的，有时会使人虚弱的疾病，影响 相当大比例的人口。椎间盘退变的最早阶段涉及 髓核区蛋白多糖的分解和随后的耗竭 阀瓣，这导致阀瓣中的静液压力降低。钠核磁共振之前已经被 用来计算核组织的固定电荷密度，随后可以 用于计算由钠离子吸引产生的渗透压。 蛋白质多聚糖的固定电荷。腰椎间盘的渗透压与 静水压力，这是椎间的一个重要的生物力学特性 光盘。目前用于评估椎间盘压力的临床技术是 椎间盘造影术，这是一种侵入性程序，已被证明会引发和加剧 腰椎间盘退变。在这项研究中，我们打算首先优化一个协议以使用 钠核磁共振仪测量完整椎间盘样本的渗透压。然而，由于 由于钠核磁共振成像的低信噪比效率，其临床应用受到限制。相比之下， T1？MRI已被证明是一种精确的测量固定电荷密度的技术 纤维软骨，如关节软骨和椎间盘。此外，由于T1？目标 质子核像传统的核磁共振成像技术一样，具有相对较高的信噪比 与钠核磁共振相比，它的效率更高，这使得它更容易在临床环境中应用。 因此，这项研究的目的是关联使用钠核磁共振测量的渗透压。 对腰椎间盘松弛时间常数的影响。通过这样做，我们可以演示T1？ MRI在无创性测量椎间盘渗透压中的临床应用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Intervertebral disc degeneration is a common and sometimes debilitating condition affecting a significant percentage of the population. The earliest stage of disc degeneration involves the breakdown and subsequent depletion of proteoglycans in the nucleus pulposus region of the disc, which results in decreased hydrostatic pressure in discs. Sodium MRI has previously been used to calculate the fixed-charge-density of the nucleus tissue, which can subsequently be used to calculate the osmotic pressure generated by the sodium cations attracted by the fixed-charge on proteoglycans. The osmotic pressure of intervertebral disc is linearly related to the hydrostatic pressure, which is an importantly biomechanical property of the intervertebral disc. The current clinical technique for the assessment of intervertebral disc pressure is discography, which is an invasive procedure that has been shown to initiate and exacerbate intervertebral disc degeneration. In this study, we intend to first optimize a protocol to use sodium MRI to measure osmotic pressure in intact intervertebral disc samples. However, due to its low signal-to-noise ratio efficiency, sodium MRI's clinical applicability is limited. In contrast, T1¿ MRI has been shown to be an accurate technique for measuring fixed-charge-density in fibrocartilage such as articular cartilage and intervertebral disc. In addition, since T1¿ targets proton nuclei like conventional MRI techniques, it has comparatively higher signal-to-noise ratio efficiency compared to sodium MRI, which makes it more readily to be applied in clinical setting. Therefore the purpose of this study is to correlate osmotic pressure measured using sodium MRI to T1¿ relaxation time constant of intervertebral discs. In doing so, we can demonstrate T1¿ MRI's clinical utility in the non-invasive measurement of intervertebral disc osmotic pressure.