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（由申请人提供）：正如亚 mSv CT 的 FOA 所认识到的那样，CT 利用率的增加和人口辐射剂量的相关增加推动了剂量减少方法的开发。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，由于对成像任务和患者特定特征的依赖性，剂量和图像质量之间的关系很复杂。拟议的工作通过硬件修改来开发任务驱动的 CT，允许为患者定制 CT 采集，并通过基于任务的性能预测框架来驱动特定成像场景的最佳剂量利用率。具体来说，将基于多孔径装置（MAD）开发一种新型轻质紧凑的X射线束调制器，该调制器能够进行高动态范围调制并适合典型的CT机架旋转速率。这种方法允许对 X 射线束的空间分布进行高度控制，包括使到达探测器和感兴趣区域 (ROI) 扫描的注量分布平坦化。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的复杂模型、成像任务定义、人类视觉系统以及应用于数据。虽然动态光束调制本身就能显着减少剂量，但通过使用为光束调制采集定制的先进统计重建算法，这些优势将与额外的减少相结合。我们假设，根据患者特定成像需求定制的任务驱动型诊断 CT 扫描仪将提供足够大的剂量减少，使得许多身体 CT 扫描场景可以达到本计划公告所定目标的亚毫希水平。建议开发和研究任务驱动 CT 的具体目标如下： 1) 开发动态光束调制硬件以集成到诊断 CT 扫描仪中。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。将传统和统计重建算法应用于光束调制数据。 3）开发动态调制CT的性能预测框架。将开发复杂的物理模型和基于任务的数学观测器，以预测位移变化、患者特定和采集相关的图像质量。 4) 制定驱动基于患者和任务的光束调制的策略。使用图像质量计划（包括可能的位移变化规范，例如 ROI 成像）和预测框架前瞻性地设计剂量限制内的最佳光束调制。 5) 评估患者和任务特定的光束调制 CT。评估结果措施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。