CEST MRI EVALUATION OF A GUINEA PIG MODEL OF ARTHRITIS

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。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， NCRR赠款不直接向子项目或子项目工作人员提供资金。 骨关节炎（OA）是一种常见的疼痛性疾病，具有肌肉骨骼系统的多因素病因，影响超过50%的65岁以上的美国人口。 关节软骨组织的退化被认为是OA发展的主要因素，是一个缓慢的过程，通常需要几十年才能完全丧失厚度，但由于创伤或外科手术，退化可能会显著加速。 Dunkin-Hartley豚鼠已被证明会发生OA，最早的检测阶段早在三到四个月大时就出现了。因此，Dunkin-Hartley豚鼠模型为OA进展的纵向研究提供了一个实用的系统。 糖胺聚糖（GAG）分子的定量评估可以帮助评估和治疗软骨退化。 不稳定蛋白质质子和大量水之间的化学交换可以使MRI对内源性蛋白质的浓度和环境的信息敏感。 化学交换饱和转移（CEST）技术是一种利用饱和不稳定质子与水的磁化交换来衰减水的磁化强度的技术，已成为一种常用的测量具有可交换质子的代谢物的方法。GAG含有氨基（-NH 2）和羟基（OH）与可用于CEST的大量水交换质子。这为测定组织中GAG含量提供了潜在的内源性标志物。因此，CEST可为GAG评估提供敏感和特异的标志物。因此，本研究的目的是开发一种CEST协议，以准确地量化在9.4 T的豚鼠软骨上的关节软骨的生化特性。

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. Osteoarthritis (OA) is a common and painful condition with a multi-factorial etiology of the musculoskeletal system affecting more than 50% of the U.S. population over 65. Degeneration of the articular cartilage tissue, which is believed to be a primary factor in the development of OA, is a slow process and typically takes decades to have full thickness loss, but can be significantly accelerated due to trauma or surgical procedures. Dunkin-Hartley guinea pigs have been shown to develop OA with the earliest stage of detection manifesting as early as three to four months of age. Therefore, the Dunkin-Hartley guinea pig model provides a practical system for the longitudinal studies of the progression of OA. Quantitative assessment of glycosaminoglycan (GAG) molecules can assist with assessment and treatment of cartilage degradation. Chemical exchange between labile protein protons and bulk water can make MRI sensitive to information about the concentrations and environments of endogenous proteins. Chemical Exchange Saturation Transfer (CEST), a technique which uses the attenuation of bulk water magnetization through magnetization exchange with saturated labile protons, has become a popular method for measurement of metabolites with exchangeable protons. GAG contains amino groups (-NH2) and hydroxyl groups (OH) that exchange protons with bulk water that can be exploited for CEST. This offers a potential endogenous marker for the determination of GAG content in tissue. Hence, CEST may provide a sensitive and specific marker for GAG assessment. Therefore, the aim of this study is to develop a CEST protocol to accurately quantify biochemical properties of the articular cartilage on guinea pig cartilage at 9.4 T.