Bolus Chasing CT Angiography Using Adaptive Control

描述（由申请人提供）： 需要静脉注射造影剂以增强CT、MR和其他成像模式中的脉管系统、器官、病变和肿瘤的显著性。多层/锥形束螺旋CT血管造影（CTA）在对比增强容积和功能成像中具有重要和直接的应用，用于诊断心血管结构、外周血管和实体器官，如脑、肺和肝。CT成像与造影剂团的传播同步可以最大化首过研究中动脉和背景之间的信号差，并可以减少造影剂剂量。CT荧光透视（CTF）允许实时断层成像，并已用于触发扫描启动与造影剂团到达同步。本项目的总体目标是在广泛的诊断应用中为多层/锥形束螺旋CTA开发一种自适应和强大的团注追踪方法。这将通过即时重建CT图像、使用系统识别方法动态预测团注传播以及自适应地改变从主动脉弓到足部的扫描间距以允许实时校正与预测的任何显著偏差来实现。R21阶段的具体目标是（1）了解正常和患病条件下的纵向团注传播特性，并将数据拟合到基于个体的扩展Hammerstein模型中，（2）制定由患者特定扩展Hammerstein模型指导的团注追踪的自适应和鲁棒控制策略，以及（3）评估所提出的团注追踪CTA的性能，并论证其技术可行性。R33阶段的具体目标是：（1）改进用于实时提取团注动力学的多层/锥形束螺旋CT图像重建和分析算法，（2）在多层/锥形束CT扫描仪上实施和优化控制策略，以及（3）在体模实验和患者研究中证明团注追踪CTA的临床可行性，并表征其性能。完成后，最佳成像和控制策略将无缝集成到多层/锥束CT扫描仪上，显著提高当前CTA的诊断性能，并将其带入下一代。

DESCRIPTION (provided by applicant): Intravenous injection of contrast media is required to enhance conspicuity of the vasculature, organs, lesions and tumors in CT, MR, and other imaging modal/ties. Multi-slice/cone-beam spiral CT angiography (CTA) has important and immediate applications in contrast enhanced volumetric and functional imaging for diagnosis of cardiovascular structures, peripheral vessels and solid organs, such as the brain, lung and liver. Synchronization of CT imaging with the propagation of contrast bolus can maximize the signal difference between arteries and background in first-pass studies and may reduce the contrast dose. CT fluoroscopy (CTF) allows real-time tomographic imaging, and has been used to trigger the scan initiation in synchrony with contrast bolus arrival. The overall goal of this project is to develop an adaptive and robust bolus-chasing methodology for multislice/cone-beam spiral CTA in a wide class of diagnostic applications. This will be achieved by instantaneously reconstructing CT images, dynamically predicting bolus propagation using a system identification approach, and adaptively varying scanning pitch from the aortic arch to the feet to allow realtime correction of any significant deviation from the prediction. The specific aims of the R21 Phase are to (1) understand longitudinal bolus propagation characteristics under normal and diseased conditions, and fit the data into an extended Hammerstein model on an individual basis, (2) formulate adaptive and robust control strategies for bolus chasing guided by a patient-specific extended Hammerstein model, and (3) evaluate the performance of the proposed bolus-chasing CTA, and demonstrate its technical feasibility. The specific aims of the R33 phase are to (1)improve multi-slice/cone-beam spiral CT image reconstruction and analysis algorithms for real-time extraction of bolus dynamics, (2) implement and optimize control strategies on a multi-slice/cone-beam CT scanner, and (3) demonstrate the clinical feasibility of bolus-chasing CTA in phantom experiments and patient studies, and characterize its performance. On completion, the optimal imaging and control strategies will have been seamlessly integrated on a multi-slice/cone-beam CT scanner, significantly improved the diagnostic performance of the current CTA, and brought it to the next generation.