Non-invasive Morphologic and Biochemical Assessment of Tendon with Novel UTE-MRI

描述(由申请人提供)： MRI已被确定为评估肌肉骨骼系统软组织(包括肌腱)的首选成像方法之一。在这种情况下，由于肌腱的固有成分具有较短的横向松弛时间(T2值，组织固有的MR特性)，在病理诊断和表征方面存在重大挑战。在典型的临床MR脉冲序列中，肌腱显示很少或没有信号。因此，以前标准的临床MRI不可能对肌腱的内部结构和定量结构/生化进行评估。超短TE(UTE)脉冲序列可以在肌腱信号衰减到非常低的水平之前检测到它，并允许表征肌腱的形态和基础结构。此前，UTE序列用于定性和定量组织定征的可行性已经确定。最近，将UTE采集方法与设计用于组织结构(T2*和T2)和生化(T1R)分析的序列相结合的磁共振技术已经开发出来。这些因素对于确定功能的完整性是重要的，这些非侵入性分析技术可能成为肌腱疾病管理的有力工具。本研究的目的是优化这些新的UTE序列，对其进行验证，并将该技术转化为临床应用，以提高对急性创伤、重复拉伤和后天或遗传性疾病造成的肌腱损伤的诊断和监测。为了实现这一点，将使用身体样本进行优化和验证。在这一阶段，UTE序列将与标准临床序列以及偏振光显微镜和评估结构完整性(胶原酶消化和羟脯氨酸检测的胶原含量)和生化组成(软骨素酶ABC处理后的二甲亚甲基蓝检测糖胺多糖含量)的分析进行比较。除了组织学验证外，还将通过拉伸和压痕测试进行生物力学验证。在该项目的最终目标中，优化和验证的序列将用于无症状志愿者以及有症状的肌腱病(过度使用)、创伤性肌腱撕裂和牛皮癣关节病患者的跟腱特征。将对这些组的有效UTE序列进行比较，并评估疼痛和功能。显然，这直接回应了在全球老龄化人口和越来越多的在现役期间受伤的退伍军人中改进肌腱和末端疾病的诊断和治疗监测的需要。

DESCRIPTION (provided by applicant): MRI has been established as one of the imaging methods of choice for evaluation of soft tissues in the musculoskeletal system, including tendons. While this is the case, significant challenges in the diagnosis and characterization of pathology exist due to the intrinsic composition of tendon which has short transverse relaxation times (T2 value, an intrinsic MR property of tissue). On typical clinical MR pulse sequences, tendons show little or no signal. As a result the internal architecture and quantitative structural/biochemical evaluation of tendon has not previously been possible with standard clinical MRI. Ultrashort TE (UTE) pulse sequences can detect signal from tendon before it has decayed to very low levels and allow characterization of tendon morphology and infrastructure. Previously, feasibility of UTE sequences for qualitative and quantitative tissue characterization has been established. Most recently, MR techniques that combine UTE acquisition methods with sequences designed for structural (T2* and T2) and biochemical (T1r) analysis of tissue has been developed. These factors are important to determine functional integrity and these non-invasive analytic techniques could be a powerful tool in the management of tendon disease. The purpose of this study is to optimize these novel UTE sequences, validate them, and translate the technology to clinical use to improve the diagnosis and monitoring of damaged tendons due to acute trauma, repetitive strain injuries, and acquired or inherited diseases. To accomplish this, cadaveric specimens will be used for optimization and validation. During this stage, UTE sequences will be compared to standard clinical sequences as well as polarized light microscopy and assays which assess structural integrity (collagen content through collagenase digestion and hydroxyproline assay) and biochemical composition (glycosaminoglycan content through dimethylmethylene blue assay following chondroitinase ABC treatment). In addition to histological validation, biomechanical validation will be performed through tensile and indentation testing. In the final aim of this project, the optimized and validated sequences will be used to characterize the Achilles tendon in asymptomatic volunteers as well as symptomatic patients with tendinosis (overuse), traumatic tendon tears, and psoriatic arthropathy. Comparison of validated UTE sequences will be made across these groups along with assessments for pain and function. It is evident that this responds directly to the need for improved diagnosis and therapeutic monitoring of tendon and enthesis diseases in a globally aging population and an increasing veteran population with injuries incurred during active duty.