A Vascular Dynamic Phantom for Dynamic Contrast Enhanced Perfusion Imaging Analys

描述（由申请人提供）：用于癌症治疗预后和评估的灌注成像的传播推动了对定量成像验证工具的日益增长的需求。目前为动态对比度增强（DCE）成像和分析提供验证的方法仅限于模拟数据和静态体模，模拟数据不考虑图像采集和伪影的变化，静态体模还不能监测动态效应及其分析。为了提供一个原位评估的成像和后处理效果的灌注系统与组织的属性相似，一个动态的流动幻影，包括一个血管网络和毛细血管交换系统，提出。该设计提供了从动脉大小的血管到毛细血管大小尺度的分布血流的物理建模，通过该模型，可以改变流动阻力以产生与预期的体内测量相当的差异灌注。这项调查的重点是开发一个可靠的，可再生的动态模型，模拟肝脏的区域解剖结构和异质性的生理功能。申报体模的一般设计将由三个组件组成：背景、组织等效体积、两个嵌入的液体再循环血管网络和一系列灌注切片，其中在供血血管的末端分支之间发生交换，进入表现出差异灌注的组织隔室，然后进入引流血管网络。使用组织支架技术，将制造具有已知的受控流动阻力的多孔区域，使得通过多孔介质的体积流量模拟在严重患病、中度受损或正常人类肝脏组织中预期的体积流量。通过每个多孔部件的体积流速将凭经验测量。动态体模系统将使用计算流体动力学来建模，以定量地估计通过体模的体积流量。具有已知灌注的物理体模将用于确认使用给定DCE-CT数据采集协议和基于隔室的DCE-CT算法采集的图像提取灌注测量值。这样的质量保证工具的可用性可以帮助跨成像中心验证灌注成像协议。这项新技术可以验证成像生物标志物在各种器官和疾病状态中的灵敏度和特异性。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。 公共卫生相关性：该项目的主要目标是开发一种可靠的，可重复的动态成像体模，充分代表通过器官系统，特别是肝脏的体积流量。体模将用于评价根据各种动态对比增强（DCE）数据采集和分析方案估计的图像提取灌注度量的准确度和精度。所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志物，这些生物标志物具有很大的潜力来驱动放射治疗期间的临床决策。

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.