Monitoring of fractures with internal fixators using weight-bearing quantitative cone beam CT

使用负重定量锥形束CT监测内固定器骨折

• 批准号: 9603931
• 负责人: JOSEPH Webster STAYMAN
• 金额: $ 36.84万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9603931
• 关键词: Address; Algorithms; Area; Asses; Binding Sites; Biological Markers; Bone Density; Bone Growth; Bone Morphogenetic Proteins; Bone callus; Cadaver; Clinical; Clinical Trials; Data; Detection; Development; Diagnostic radiologic examination; Dose; Evaluation; Exhibits; Fracture; Fracture Fixation; Fracture Healing; Future; Health; Health Care Costs; Healthcare; Hospitalization; Human; Image; Imagery; Impaired wound healing; Implant; Internal Fixators; Intramedullary Nailing; Knowledge; Lead; Least-Squares Analysis; Limb structure; Measurement; Measures; Mechanics; Metals; Methods; Minerals; Modeling; Monitor; Morphologic artifacts; Motion; Operative Surgical Procedures; Patients; Performance; Photons; Physiologic pulse; Pilot Projects; Protocols documentation; Radiology Specialty; Reproducibility; Research; Resolution; Roentgen Rays; Scanning; Shapes; Source; Starvation; Structure; System; Techniques; Technology; Testing; Three-Dimensional Imaging; Translating; Ultrasonography; Visual; Weight-Bearing state; Work; attenuation; base; bone; bone healing; clinical translation; cone-beam computed tomography; density; detector; experimental study; high resolution imaging; image reconstruction; imaging approach; imaging system; implantation; improved; innovation; metal complex; mineralization; novel; novel strategies; novel therapeutics; operation; quantitative imaging; reconstruction; repaired; sample fixation; tomography

PROJECT SUMMARY / ABSTRACT The healthcare burden of fractures is exacerbated for patients who suffer from non-unions and delayed unions. Prediction of non-unions and development of new therapies stimulating bone growth is challenged by a lack of quantitative, non-invasive tests to simultaneously assess the two primary aspects of bone healing: (i) mineral density of the callus and fracture gap; and (ii) mechanical stability under weight-bearing. To address this challenge, we proposed to use a novel extremity cone-beam CT system (CBCT) that provides a unique capability of weight-bearing 3D imaging at high spatial resolution. This will allow measurement of the motion of bone fragments by estimating their displacement between weight-bearing and non-weight-bearing scans of the extremity. In addition, much like conventional CT, CBCT can perform bone mineral density (BMD) measurements of the fracture. To enable quantitative weight-bearing assessment of fracture repair on extremities CBCT, artifacts and image nonuniformity due to metal fixation hardware must be mitigated. The scientific premise of this work is that the effects of metal hardware can be minimized by a combination of novel Dual Energy (DE) techniques suitable for extremities CBCT and advanced model-based image reconstruction (MBIR) incorporating prior knowledge of the surgical hardware. DE imaging will provide a robust correction of the attenuation value inaccuracy due to beam hardening. Efficient, single-scan implementation of DE CBCT will be achieved using the innovative multi-source configuration on the extremities CBCT scanner. The Known-Component Reconstruction algorithm (KCR) will be used to address metal-induced photon starvation and nonlinear partial volume effects by exploiting prior knowledge of the shape and pose of the metal component. Inherent in this approach is a component registration step that will provide a precise estimate of implant deformation under weight-bearing, resulting in a novel approach to asses fracture stability. The following specific aims will be pursued: 1) Enable Dual Energy CBCT from multi-source CBCT data by means of an novel DE MBIR algorithm and optimized DE imaging protocols to yield detection of ~5% relative change in bone mineral density in phantoms; 2) Integrate prior knowledge of surgical hardware in MBIR DE reconstruction by exploiting accurate (~0.5 mm Target Registration Error) deformable 3D-2D registration of fracture fixation hardware to estimate component pose and deformation; 3) Perform clinical translation of the Known-Component DE algorithms in implanted cadaveric extremities under controlled load and in pilot patient study. Fracture patients will be imaged at 2, 4, 8 and 12 weeks post-fracture to demonstrate detection of changes in callus mineralization during fracture repair. This research will establish an innovative quantitative imaging approach for simultaneous, non-invasive assessment of two primary biomarkers of fracture repair: mineralization of the callus and fracture gap, and mechanical stability of the bone-implant construct under load.

项目概要/摘要 对于不愈合和延迟愈合的患者来说，骨折的医疗负担会加重。 骨不连的预测和刺激骨生长的新疗法的开发因缺乏 定量、非侵入性测试，可同时评估骨愈合的两个主要方面：(i) 矿物质 愈伤组织和骨折间隙的密度； (ii) 承重下的机械稳定性。为了解决这个问题 挑战，我们建议使用一种新型的四肢锥形束 CT 系统 (CBCT)，它提供了独特的功能 高空间分辨率的承重 3D 成像。这将允许测量骨骼的运动 通过估计碎片在承重和非承重扫描之间的位移 末端。此外，与传统 CT 非常相似，CBCT 可以进行骨矿物质密度 (BMD) 测量 骨折的情况。为了能够对四肢骨折修复的 CBCT 进行定量承重评估， 必须减轻金属固定硬件造成的伪影和图像不均匀性。科学前提是 这项工作是通过结合新颖的双能 (DE) 来最大限度地减少金属硬件的影响 适合四肢的技术 CBCT 和先进的基于模型的图像重建 (MBIR) 结合 手术硬件的先验知识。 DE 成像将提供衰减值的稳健校正 由于光束硬化而导致的不准确性。 DE CBCT 的高效、单次扫描实施将通过使用 四肢 CBCT 扫描仪上的创新多源配置。已知组件重建 算法（KCR）将用于解决金属引起的光子饥饿和非线性部分体积效应 利用金属部件的形状和姿态的先验知识。这种方法的本质是 组件配准步骤将提供负重下植入物变形的精确估计， 从而产生了一种评估断裂稳定性的新方法。将追求以下具体目标： 1) 通过新颖的 DE MBIR 算法和优化的 DE，根据多源 CBCT 数据进行双能量 CBCT 成像协议可检测体模中骨矿物质密度约 5% 的相对变化； 2）整合 通过利用精确的（~0.5 mm 目标）进行 MBIR DE 重建中手术硬件的先验知识 配准误差）骨折固定硬件的可变形 3D-2D 配准，以估计组件位姿和 形变; 3) 在植入尸体中执行已知组件 DE 算法的临床翻译 受控负荷下的四肢和试点患者研究。骨折患者将在 2、4、8 和 12 日进行影像检查 骨折后几周，以证明骨折修复过程中愈伤组织矿化变化的检测。这 研究将建立一种创新的定量成像方法，用于同步、非侵入性评估 骨折修复的两个主要生物标志物：愈伤组织和骨折间隙的矿化以及机械稳定性 负载下的骨植入物结构。