Ultrashort Echo Time (UTE) Magnetic Resonance Imaging of Bone

骨超短回波时间 (UTE) 磁共振成像

• 批准号: 9005600
• 负责人: Jiang Du
• 金额: $ 51.96万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-17 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9005600
• 关键词: Affect; Age; Binding; Biochemical; Biochemical Markers; Biological Markers; Biomechanics; Body mass index; Bone Density; Bone Marrow; Bone Matrix; Cattle; Collagen; Control Groups; Diagnosis; Dual-Energy X-Ray Absorptiometry; Elderly; Ethnic Origin; Evaluation; Fatty acid glycerol esters; Fracture; Goals; Gold; Head and neck structure; Human; Image; Imaging Techniques; Isotopes; Leg; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Marrow; Measurement; Measures; Mechanics; Medicine; Minerals; Modeling; Monitor; NMR Spectroscopy; Neck; Obesity; Osteoporosis; Physiologic pulse; Play; Porosity; Postmenopause; Premenopause; Property; Quantitative Evaluations; Reference Standards; Relaxation; Risk; Risk Factors; Role; Sampling; Scanning; Signal Transduction; Soft Tissue Disorder; Specimen; Staging; Structure of greater trochanter of femur; Techniques; Testing; Therapeutic; Time; Triglycerides; Unsaturated Fats; Water; Woman; Work; X-Ray Computed Tomography; age group; base; bone; bone loss; bone quality; clinical sequencing; cohort; density; improved; in vivo; in vivo imaging; insight; interest; millisecond; novel; osteoporosis with pathological fracture; public health relevance; quantitative imaging; substantia spongiosa; temporal measurement; two-dimensional

 DESCRIPTION (provided by applicant): Quantitative imaging of bone has been of central importance in medicine since Roentgen produced the first radiograph in 1895. The current gold standard technique DEXA measures bone mineral density (BMD). However, the majority of bone, including the organic matrix and bone water which together occupy ~60% of bone by volume is inaccessible. BMD by itself only predicts osteoporotic fractures with an accuracy of 30-50%. The overall fracture risk increases 13-fold from ages 60 to 80, but BMD alone only predicts a doubling of the fracture risk. In addition, recent studies demonstrate that bone marrow adiposity plays an active role in affecting bone quantity and quality. There is considerable interest in more comprehensive evaluation of bone quality using information not only about bone mineral, but organic matrix, bone water and marrow fat. All of these factors may play a role in maintaining the biomechanical integrity of cortical and trabecular bone. Magnetic resonance imaging (MRI) is routinely used in the diagnosis of soft tissue disease. However, bone is "invisible" using all clinical sequences due to its short T2*. We have developed 2D and 3D UTE sequences with TEs of 8 µs that are ~1000 times shorter than conventional TEs. This makes it possible to detect multiple water components in cortical bone, and fat content and composition in trabecular bone. The pore water content provides a surrogate measure of cortical porosity. Collagen-bound water provides an indirect measure of organic matrix density. Marrow fat content and composition provide BMD independent fracture risk factors. It would be a major advance to develop UTE MRI techniques to evaluate porosity and organic matrix density in cortical bone, as well as marrow fat content and composition in trabecular bone. This study aims to develop and combine novel 3D UTE MRI techniques to evaluate cortical and trabecular bone offering full insight into bone characterization and correlation with function. To achieve thi goal, in Aim 1 we will evaluate 3D UTE MRI techniques for assessment of cortical bone. We will determine the accuracy of UTE measurement of collagen-bound and pore water, and correlate UTE MRI metrics (collagen-bound and pore water content, T1, T2* and MTR) with biomechanical properties of cortical bone. In Aim 2 we will evaluate 3D UTE MRI techniques for evaluation of trabecular bone. We will determine the accuracy of 3D UTE MRI measurement of marrow fat content and composition and correlate 3D UTE MRI metrics with those from MR spectroscopy (MRS) as well as biomechanical properties of trabecular bone. In Aim 3 we will apply the validated 3D UTE MRI techniques to study one group of premenopausal women and two groups of postmenopausal women with slow or fast bone loss. We will compare the 3D UTE MRI and MRS metrics in different groups and correlate the results with BMD and biochemical markers. This work will provide accurate panels of 3D UTE MRI and MRS based biomarkers which may be important for assessing bone quality, and may have a major impact on the diagnosis and therapeutic monitoring of OP.

 描述（由申请人提供）：自 1895 年伦琴制作出第一张放射线照片以来，骨的定量成像一直在医学中发挥着重要作用。当前的黄金标准技术 DEXA 测量骨矿物质密度 (BMD)，但是，大多数骨，包括骨密度。有机基质和骨水合计占骨体积的约 60%，BMD 本身只能预测骨质疏松性骨折，准确度为 30-50%。从 60 岁到 80 岁，骨密度增加 13 倍，但仅预测骨折风险加倍。此外，最近的研究表明，骨髓肥胖在影响骨量和骨质量方面发挥着积极作用，人们对更全面的研究非常感兴趣。评估骨质量不仅使用骨矿物质信息，还使用有机基质、骨水和骨髓脂肪信息，所有这些因素都可能在维持皮质骨和骨小梁的生物力学完整性方面发挥作用。 (MRI) 通常用于诊断软组织疾病，但由于其 T2* 较短，因此使用所有临床序列都“看不到”骨骼，我们开发了 TE 为 8 µs 的 2D 和 3D UTE 序列，约为 1000 倍。比传统的 TE 更短，这使得检测皮质骨中的多种水成分以及小梁骨中的脂肪含量和成分成为可能。孔隙水含量提供了皮质孔隙度的替代测量。胶原结合水可间接测量骨髓脂肪含量和成分，从而提供独立于 BMD 的骨折风险因素。开发 UTE MRI 技术来评估皮质骨的孔隙度和有机基质密度将是一项重大进步。本研究旨在开发并结合新型 3D UTE MRI 技术来评估皮质骨和骨小梁，从而全面了解骨特征及其与功能的相关性。目标 1 我们将评估用于评估皮质骨的 3D UTE MRI 技术 我们将确定 UTE 测量胶原蛋白结合和孔隙水的准确性，并将 UTE MRI 指标（胶原蛋白结合和孔隙水含量、T1、T2* 和）关联起来。 MTR）与皮质骨的生物力学特性在目标 2 中，我们将评估用于评估骨小梁的 3D UTE MRI 技术我们将确定 3D UTE MRI 的准确性。测量骨髓脂肪含量和成分，并将 3D UTE MRI 指标与 MR 光谱 (MRS) 以及骨小梁的生物力学特性相关联。在目标 3 中，我们将应用经过验证的 3D UTE MRI 技术来研究一组绝经前妇女和女性。我们将比较不同组的 3D UTE MRI 和 MRS 指标，并将结果与​​ BMD 和 BMD 相关联。这项工作将提供基于 3D UTE MRI 和 MRS 的准确生物标志物组合，这对于评估骨质量可能很重要，并且可能对 OP 的诊断和治疗监测产生重大影响。