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

描述（由申请人提供）： MRI已被确立为评价肌肉骨骼系统软组织（包括肌腱）的首选成像方法之一。尽管如此，由于肌腱的固有成分具有短的横向弛豫时间（T2值，组织的固有MR特性），因此在病理诊断和表征方面存在重大挑战。在典型的临床MR脉冲序列上，肌腱显示很少或没有信号。因此，肌腱的内部结构和定量结构/生化评价以前不可能使用标准临床MRI。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肌腱信号，并可以表征肌腱形态和基础结构。以前，已经确定了UTE序列用于定性和定量组织表征的可行性。最近，已经开发了将联合收割机UTE采集方法与设计用于组织的结构（T2* 和T2）和生物化学（T1 r）分析的序列相结合的MR技术。这些因素对于确定功能完整性很重要，这些非侵入性分析技术可能是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，验证它们，并将该技术转化为临床应用，以改善对急性创伤，重复性劳损以及获得性或遗传性疾病所致肌腱损伤的诊断和监测。为了实现这一点，将使用尸体标本进行优化和确认。在此阶段，将UTE序列与标准临床序列以及偏振光显微镜和测定进行比较，以评估结构完整性（通过胶原酶消化和羟脯氨酸测定的胶原含量）和生化组成（软骨素酶ABC处理后通过二甲基亚甲蓝测定的糖胺聚糖含量）。除组织学确认外，还将通过拉伸和压痕试验进行生物力学确认。在本项目的最终目标中，优化和验证的序列将用于表征无症状志愿者以及肌腱病（过度使用）、创伤性肌腱撕裂和银屑病关节病的症状性患者的跟腱。将在这些组中比较经验证的UTE序列，同时进行疼痛和功能评估沿着。很明显，这直接响应了在全球老龄化人口中改善肌腱和附着点疾病的诊断和治疗监测的需求，以及在现役期间受伤的退伍军人人数的增加。

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.