Task-driven dynamic beam modulation for high-performance,low-dose CT.

用于高性能、低剂量 CT 的任务驱动动态光束调制。

• 批准号: 8926430
• 负责人: JOSEPH Webster STAYMAN
• 金额: $ 62.05万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8926430
• 关键词: Algorithms; Attention; Automobile Driving; Cadaver; Characteristics; Clinical Research; Complex; Computer software; Coupled; Data; Dependency; Development; Devices; Diagnostic; Diagnostic Imaging; Dose; Evaluation; Health; Heterogeneity; Human; Image; Image Analysis; Individual; Lung; Maps; Measurement; Measures; Methods; Modeling; Modification; NIH Program Announcements; Nature; Noise; Organ; Outcome Measure; Patients; Pattern; Performance; Physics; Pilot Projects; Population; Protocols documentation; Radiation; Research; Residual state; Resolution; Rotation; Scanning; Site; Solutions; Spatial Distribution; Statistical Models; System; Task Performances; Techniques; Technology; Testing; Translational Research; Tube; Variant; Visual system structure; Work; X-Ray Computed Tomography; base; beam dynamics; bone; computerized data processing; design; detector; improved; interest; low-dose spiral CT; meetings; novel; patient population; physical model; preference; quantitative imaging; radiosensitive; reconstruction; research study; soft tissue; transmission process

DESCRIPTION (provided by applicant): As recognized in the FOA for sub-mSv CT, the increased CT utilization and the associated increase in population radiation dose motivates the development of dose reduction methods. Any meaningful strategies for dose reduction must be coupled with an analysis of image quality. However, the relationship between dose and image quality is complex due to dependencies on the imaging task and patient-specific characteristics. The pro- posed effort develops task-driven CT through hardware modifications that permit customizing the CT acquisition to the patient, and through a task-based performance prediction framework that is used to drive optimal dose utilization for specific imaging scenarios. Specifically, a novel lightweight and compact x-ray beam modulator capable of high dynamic range modulations and suitable for typical CT gantry rotation rates will be developed based on multiple aperture devices (MADs). This approach allows for a high degree of control over the spatial profile of the x-ray beam including flattening of fluence profile arriving at the detector nd region-of- interest (ROI) scanning. Actuation of these devices will be driven by an image quality plan based on a 3D scout volume and a task-based detectability framework that includes sophisticated models of the measurement physics, imaging task definitions, the human visual system, and the particular reconstruction approaches applied to the data. While dynamic beam modulation alone yields significant dose reductions, these advantages will be synergized with additional reductions through the use of advanced statistical reconstruction algorithms customized for beam modulated acquisitions. We hypothesize that a task-driven diagnostic CT scanner tailored to the specific imaging needs of the patient will provide large enough dose reductions that many body CT scanning scenarios can be driven to sub-mSv levels as targeted by this program announcement. The following Specific Aims are proposed to develop and investigate task-driven CT: 1) Develop dynamic beam modulation hardware for integration into diagnostic CT scanners. Design, characterize, and integrate the MAD modulators into CT acquisition systems. 2) Create a reconstruction framework for dynamically modulated CT acquisitions. Adapt both traditional and statistical reconstruction algorithms to beam modulated data. 3) Develop a performance prediction framework for dynamically modulated CT. A sophisticated physical model and task-based mathematical observer will be developed that predicts the shift-variant, patient-specific, and acquisition-dependent image quality. 4) Develop strategies for driving patient- and task-based beam modulations. Using image quality plans (including possibly shift-variant specification, e.g. ROI imaging) and the prediction framework prospectively design optimal beam modulations within dose constraints. 5) Assess patient- and task-specific beam-modulated CT. Evaluation outcome measures will include quantitative imaging performance metrics, absorbed dose measurements and dose maps based on Monte Carlo estimation, and an observer preference test using cadaver studies including relations to minimum dose protocols.

描述（由申请方提供）：正如FOA中关于亚mSv CT的认识，CT利用率的增加和人群辐射剂量的相关增加推动了剂量降低方法的开发。任何有意义的剂量减少策略都必须与图像质量分析相结合。然而，剂量和图像质量之间的关系是复杂的，由于依赖于成像任务和患者的具体特征。所提出的努力通过允许针对患者定制CT采集的硬件修改以及通过用于驱动特定成像场景的最佳剂量利用的基于任务的性能预测框架来开发任务驱动的CT。具体而言，一种新型的轻量级和紧凑的X射线束调制器，能够高动态范围调制和典型的CT机架旋转速率适合将开发基于多孔径设备（MAD）。这种方法允许对X射线束的空间轮廓进行高度控制，包括使到达检测器的注量轮廓变平和感兴趣区域（ROI）扫描。这些设备的驱动将由基于3D侦察体积和基于任务的可检测性框架的图像质量计划驱动，该框架包括测量物理学的复杂模型、成像任务定义、人类视觉系统和应用于数据的特定重建方法。虽然单独的动态射束调制会显着减少剂量，但这些优势将通过使用针对射束调制采集定制的高级统计重建算法与额外的减少协同作用。我们假设，根据患者的特定成像需求量身定制的任务驱动诊断CT扫描仪将提供足够大的剂量降低，使许多身体CT扫描场景可以被驱动到本计划公告所针对的亚mSv水平。提出了以下具体目标来开发和研究任务驱动CT：1）开发用于集成到诊断CT扫描仪中的动态射束调制硬件。设计、表征MAD调制器并将其集成到CT采集系统中。2)为动态调制CT采集创建重建框架。使传统和统计重建算法适应波束调制数据。3)开发动态调制CT的性能预测框架。将开发一个复杂的物理模型和基于任务的数学观测器，用于预测移位变量、患者特异性和采集相关的图像质量。4)制定用于驱动基于患者和任务的射束调制的策略。使用图像质量计划（可能包括移位变量规范，例如ROI成像）和预测框架，前瞻性地设计剂量约束内的最佳射束调制。5)评估患者和任务特定的波束调制CT。评价结果指标将包括定量成像性能指标、吸收剂量测量和基于蒙特卡罗估计的剂量图，以及使用尸体研究（包括与最小剂量方案的关系）的观察者偏好测试。