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(申请人提供)：自1895年伦琴公司制作第一张X光片以来，骨的定量成像在医学上一直是至关重要的。目前的黄金标准技术DEXA测量骨密度(BMD)。然而，大部分骨，包括有机基质和骨水，加起来占骨体积的60%是无法获得的。骨密度本身只能预测骨质疏松性骨折，准确率为30-50%。从60岁到80岁，骨折的总体风险增加了13倍，但仅BMD一项只能预测骨折风险的两倍。此外，最近的研究表明，骨髓肥胖症在影响骨骼数量和质量方面发挥着积极的作用。人们对不仅使用骨矿物质，而且使用有机基质、骨水和骨髓脂肪的信息来更全面地评估骨质量有相当大的兴趣。所有这些因素都可能在维持皮质骨和松质骨的生物力学完整性方面发挥作用。磁共振成像(MRI)是软组织疾病的常规诊断方法。然而，由于其较短的T2*，骨在所有临床序列中都是“看不见的”。我们已经开发了2D和3D UTE序列，其TES为8微米S，比传统TES短约1000倍。这使得能够检测皮质骨中的多种水分成分，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度的替代指标。胶原蛋白结合水提供了一种间接测量有机基质密度的方法。骨髓脂肪含量和组成提供了骨密度独立的骨折危险因素。UTE MRI技术的发展将是评估皮质骨的孔隙率和有机基质密度以及小梁骨的骨髓脂肪含量和成分的重大进展。这项研究旨在开发和结合新的3D UTE MRI技术来评估皮质骨和松质骨，从而全面了解骨的特征及其与功能的相关性。为了实现这一目标，在目标1中，我们将评估3D UTE MRI技术在皮质骨评估中的应用。我们将确定UTE测量胶原结合和孔隙水的准确性，并将UTE MRI指标(胶原结合和孔隙水含量、T1、T2*和MTR)与皮质骨的生物力学特性相关联。在目标2中，我们将评估3D UTE MRI技术在评估松质骨中的作用。我们将确定3D UTE MRI测量骨髓脂肪含量和成分的准确性，并将3D UTE MRI测量与磁共振波谱(MRS)的测量结果以及松质骨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两组有缓慢或快速骨丢失的绝经后妇女。我们将比较不同组的3D UTE、MRI和MRS指标，并将结果与BMD和生化标记物进行关联。这项工作将提供基于3DUTE MRI和MRS的生物标志物的准确面板，这些生物标志物可能对评估骨质量很重要，并可能对OP的诊断和治疗监测产生重大影响。