Quantitative Magnetic Resonance and Ultrasound Imaging of Human Rotator Cuff Muscle and Tendon

肩袖（RC）是盂肱关节的主要动力稳定器，功能障碍可导致 通过力偶损失、肩关节功能恶化以及最终 软骨退化和袖套关节病。全层钢筋混凝土肌腱撕裂是常见的，发生在>20%的 当非手术治疗失败时，通常进行手术修复。虽然 肌肉纤维化和肌腱变性是增加手术复杂性和导致 为了降低患者结局评分，它们很难进行非侵入性评估，包括使用传统的 磁共振成像（MRI）和超声（US），这两种最广泛使用的成像方式。 最近，新的超短回波时间磁化传递（UTE-MT）MRI技术已经被用于 用于评估肌腱质量，初步结果显示对魔角效应不敏感， 与胶原损失的强相关性，以及区分肌腱病变组的能力。然而，在这方面， 当应用于退化肌肉时，脂肪的存在差异会降低该技术的准确性，因为 已经提出了几种新的脂肪抑制方法。肌肉脂肪的超声定量和 还尝试了使用常规B模式图像进行纤维化，但成功有限。 该提案的目标是开发、优化、验证和翻译新的MRI和US技术 用于全面定量评价RC肌肉和肌腱胶原异常和纤维化。在 第一个技术开发目标是优化具有多种脂肪抑制方法的新型UTE-MT， 实施，并将确定具有优化参数的上级版本。此外，定量 将实施基于原始射频数据的US，并将实施新的组织特异性散射模型。 创造第一个假设是新的定量UTE-MT与脂肪抑制和定量US 可以开发和优化结合用于肌腱和肌肉的组织特异性模型。第二个目标， 具有单侧巨大RC腱撕裂的对照大鼠模型用于诱导肌肉和腱变性。 新的定量MRI和US技术将与现有的定量MRI和US技术进行验证和比较。 技术.第二个假设是，这些新技术可以纵向实施， 这是可重复的，并且将更好地与参考标准组织学测量相关。第三个人类 translational aim将这些新技术带到了临床。两个年龄和性别匹配的患者队列 将进行成像，包括无全层RC撕裂的个体和有全层RC撕裂的个体 患者将接受手术修复，并采集小活检样本。第三个假设是小说 定量MRI和US技术可用于临床进行全面的非侵入性评估 RC肌肉和肌腱。

The rotator cuff (RC) is the primary dynamic stabilizer of the glenohumeral joint and dysfunction can lead to abnormal joint kinematics through loss of force couples, deterioration of shoulder function, and ultimately cartilage degeneration and cuff arthropathy. Full-thickness RC tendon tears are common, occurring in >20% of the adult population, and when non-operative management fails, surgical repair is often performed. Although muscle fibrosis and tendon degeneration are important variables that can increase surgical complexity and lead to lower patient outcome scores, they are difficult to evaluate non-invasively, including with conventional magnetic resonance imaging (MRI) and ultrasound (US), the two most widely used imaging modalities. Recently the novel ultrashort echo time magnetization transfer (UTE-MT) MRI technique has been developed to assess tendon quality, and preliminary results showed insensitivity to the magic angle effect, a strong correlation with collagen loss, and the capability to distinguish between tendinopathy groups. However, the variable presence of fat diminishes the accuracy of the technique when applied to degenerated muscle, for which several new fat-suppression methods have been proposed. Ultrasound quantification of muscle fat and fibrosis has also been attempted using routine B-mode images with limited success. The goal of this proposal is to develop, optimize, validate, and translate novel MRI and US techniques for comprehensive quantitative evaluation of RC muscle and tendon collagen abnormalities and fibrosis. In the first technical development aim, novel UTE-MT with various fat-suppression methods will be optimized and implemented, and the superior version with optimized parameters will be determined. In addition, quantitative US based on raw radiofrequency data will be implemented and novel tissue-specific scattering models will be created. The first hypothesis is that novel quantitative UTE-MT with fat-suppression and quantitative US incorporating tissue-specific models for tendon and muscle can be developed and optimized. In the second aim, a controlled rat model with unilateral massive RC tendon tear is used to induce muscle and tendon degeneration. The novel quantitative MRI and US techniques will be validated and compared alongside existing quantitative techniques. The second hypothesis is that these novel techniques can be implemented longitudinally, are reproducible, and will better correlate with reference standard histological measurements. The third human translational aim brings these new techniques to the clinic. Two age- and gender-matched cohorts of patients will be imaged, including individuals without full-thickness RC tears and individuals with full-thickness RC tears who will undergo surgical repair with acquisition of small biopsy samples. The third hypothesis is that the novel quantitative MRI and US techniques can be translated to the clinic for comprehensive, non-invasive assessment of RC muscle and tendon.