A Vascular Dynamic Phantom for Dynamic Contrast Enhanced Perfusion Imaging Analys

描述（由申请人提供）：随着灌注成像在癌症治疗预后和评估方面的普及，对定量成像验证工具的需求日益增加。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，这不能解释图像采集和伪影的差异，以及静态幻影，这还不能监测动态效果及其分析。为了提供对具有类似组织特性的灌注系统的成像和后处理效果的原位评估，提出了一个由血管网络和毛细血管交换系统组成的动态流动幻象。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，通过这种模型可以改变流动阻力，从而产生与预期的体内测量相当的差异灌注。本研究的重点是开发一个可靠的，可重复的动态模型，模拟肝脏的区域解剖和异质生理功能。拟建体的总体设计将由三个部分组成：一个背景，组织等效体积，两个嵌入的流体再循环血管网络，以及一系列灌注部分，在这些部分中，供血血管的末端分支之间发生交换，进入表现不同灌注的组织腔室，然后进入排水血管网络。使用组织支架技术，可以制造出具有已知的、可控制的流动阻力的多孔区域，这样通过多孔介质的体积流动就可以模拟严重病变、中度损伤或正常人类肝脏组织中的体积流动。通过每个多孔组分的体积流量将通过经验测量。采用计算流体动力学对动态模体系统进行建模，定量估计通过模体的体积流量。具有已知灌注的物理模型将用于验证使用给定DCE-CT数据采集协议和基于隔室的DCE-CT算法获得的图像提取灌注测量值。这种质量保证工具的可用性可能有助于验证各成像中心的灌注成像方案。这项新技术可以验证成像生物标志物在不同器官和疾病状态下的敏感性和特异性。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。

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.