A Vascular Dynamic Phantom for Dynamic Contrast Enhanced Perfusion Imaging Analys

描述(由申请人提供)：由于灌注成像在癌症治疗、预后和评估中的传播，对定量成像验证工具的需求日益增加。当前为动态对比度增强(DCE)成像和分析提供验证的方法已经局限于模拟数据，其没有考虑图像采集和伪影中的差异，以及静态幻影，其还不监视动态效果及其分析。为了提供对具有类似组织特性的灌流系统的成像和后处理效果的现场评估，提出了一种由血管网络和毛细血管交换系统组成的动态流动体模。该设计提供了从动脉大小的血管到毛细血管大小的分布血流的物理模型，通过该模型可以改变流动阻力，以产生与预期的活体测量相当的差异灌注量。这项研究的重点是开发一种可靠的、可重复的动态体模，模拟肝脏的局部解剖和不同的生理功能。提出的体模的总体设计将由三个部分组成：背景、组织当量体积、两个嵌入的液体再循环血管网络和一系列灌流部分，其中供血血管的末端分支之间发生交换，进入表现不同灌流的组织室，然后进入引流血管网络。利用组织支架技术，将制造出具有已知可控流动阻力的多孔区，从而使通过多孔介质的体积流动模拟在严重病变、中度损伤或正常人体肝脏组织中预期的体积流动。将根据经验测量通过每个多孔组件的体积流量。将使用计算流体动力学对动态体模系统进行建模，以定量地估计通过体模的体积流量。已知灌注的物理体模将用于验证图像提取的灌注测量，该测量使用给定的DCE-CT数据采集协议和基于间隔的DCE-CT算法获取。这种质量保证工具的可用性可能有助于验证跨成像中心的灌注成像协议。这项新技术可以在不同器官和疾病状态下验证成像生物标记物的敏感性和特异性。最终，这将通过更好的治疗计划延长患者的生命，并有助于降低与高剂量放射治疗相关的风险。 与公共卫生相关：该项目的主要目标是开发一种可靠的、可重现的动态成像体模，充分表示通过器官系统的体积流动，特别是肝脏。该模型将用于评估从各种动态对比增强(DCE)数据采集和分析协议估计的图像提取的灌注度量的准确性和精确度。提出的体模可用于验证现有的基于成像的血液供应生物标记物，这些标记物在放射治疗期间具有巨大的潜力来驱动临床决策。

DESCRIPTION (provided by applicant): The increasing need for a quantitative imaging validation tool is fueled by the propagation of perfusion imaging for cancer treatment prognosis and evaluation. Current methods of providing validation for dynamic contrast-enhanced (DCE) imaging and analyses have been limited to simulated data, which do not account for variances in image acquisition and artifacts, and static phantoms, which do not yet monitor dynamic effects and their analyses. To provide an in situ assessment of the imaging and post-processing effects on a perfused system with properties similar to tissue, a dynamic flow phantom, consisting of a vascular network and a capillary exchange system, is proposed. The design offers the physical modeling of distributed blood flow from arterial-sized vessels down to a capillary-like size scale, through which flow resistance can be varied to produce differential perfusion comparable to expected in vivo measurements. This investigation focuses on the development of a reliable, reproducible dynamic phantom that models the liver's regional anatomy and heterogeneous physiological function. The general design for the proposed phantom would consist of three components: a background, tissue equivalent volume, two embedded fluid re-circulating vascular network, and a series of perfused sections, where exchange occurs between the terminal branches of the feeding vessels into tissue compartments exhibiting differential perfusion, and then into a network of draining vessels. Using tissue scaffold techniques, porous regions with known, controlled flow resistance would be fabricated, such that the volumetric flow through porous media mimics the volumetric flow expected in severely diseased, moderately damaged or normal human liver tissue. The volumetric flow rate through each porous component would be measured empirically. The dynamic phantom system would be modeled using computation fluid dynamics to quantitatively estimate the volumetric flow through the phantom. The physical phantom, with a known perfusion, will be used to validate image- extracted perfusion measurements acquired using a given DCE-CT data acquisition protocol and compartment-based DCE-CT algorithms. The availability of such a quality assurance tool may help to validate perfusion imaging protocols across imaging centers. This new technology can enable the validation of imaging biomarkers' sensitivity and specificity across various organs and disease states. Ultimately, this will prolong the lives of patients through better treatment planning, and help reduce the risks associated with high-dose radiation treatment. PUBLIC HEALTH RELEVANCE: The primary goal of this project is to develop a reliable, reproducible dynamic imaging phantom that adequately represents volumetric flow through an organ system, particularly the liver. The phantom will be used to evaluate the accuracy and precision of image-extracted perfusion metrics that are estimated from various Dynamic Contrast Enhanced (DCE) data acquisition and analysis protocols. The proposed phantom can be used to validate existing imaging-based biomarkers of blood supply that have great potential to drive clinical decisions during radiation therapy treatment.