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（由适用提供）：自从罗恩根（Roentgen）于1895年产生了第一个X光片以来，骨骼的定量成像一直至关重要。当前的金标准技术DEXA测量骨矿物质密度（BMD）。然而，大多数骨骼，包括有机基质和骨水，占据骨骼占据约60％的骨骼是无法访问的。 BMD本身仅预测骨质疏松骨折的精度为30-50％。总体断裂风险从60岁增加到80岁，但仅BMD仅预测断裂风险的增加一倍。此外，最近的研究表明，骨髓肥胖在影响骨骼数量和质量方面起着积极作用。不仅使用有关骨矿物质，有机基质，骨水和骨髓脂肪的信息，人们对对骨质质量进行更全面的评估引起了极大的兴趣。所有这些因素可能在维持皮质和小梁骨的生物力学完整性方面发挥作用。磁共振成像（MRI）通常用于诊断软组织疾病。但是，由于其短T2*，使用所有临床序列是“不可见的”。我们已经开发了2D和3D UTE序列，其TES为8 µs，比常规TE短约1000倍。这使得可以检测皮质骨中的多个水成分，以及小梁骨中的脂肪含量和成分。孔隙水含量提供了皮质孔隙率的替代测量。结合胶原蛋白的水提供了有机基质密度的间接测量。骨髓脂肪含量和成分提供了BMD独立的断裂危险因素。开发UTE MRI技术来评估皮质骨中的孔隙率和有机基质密度以及小梁骨中的骨髓脂肪含量和组成将是一个重大进步。这项研究旨在开发和结合新型的3D UTE MRI技术，以评估皮质和小梁骨，从而完全洞悉骨骼表征和与功能的相关性。为了实现这一目标，在目标1中，我们将评估3D UTE MRI技术评估皮质骨。我们将确定胶原结合和孔隙水的UTE测量的准确性，并将UTE MRI指标（结合胶原蛋白和孔隙水含量，T1，T2*和MTR）与皮质骨的生物力学特性相关联。在AIM 2中，我们将评估3D UTE MRI技术以评估小梁骨。我们将确定骨髓脂肪含量和组成的3D UTE MRI测量的准确性，并将3D UTE MRI指标与MR光谱法（MRS）以及小梁骨的生物力学特性相关。在AIM 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两组绝经后妇女，这些妇女具有缓慢或快速的骨质流失。我们将在不同组中比较3D UTE MRI和MRS指标，并将结果与​​BMD和生化标记相关联。这项工作将提供3D UTE MRI和基于MRS的生物标志物的精确面板，这对于评估骨骼质量可能很重要，并且可能对OP的诊断和治疗监测产生重大影响。