Five dimensional analysis of tumor-induced angiogenesis using CT perfusion imaging_with numerical simulation of fluid dynamics of contrast medium

目的建立功能计算机断层扫描（CT）成像作为评估肿瘤诱导血管生成的方法。材料与方法采用4通道多排CT系统对14例肾细胞癌进行功能CT成像。利用计算离散化方法，通过造影剂的双室建模，对功能CT成像进行数学分析。该模型纳入了造影剂的扩散动力学，包括从毛细血管渗漏到血管外腔室和从血管外到毛细血管腔室的巴克通量。统计分析功能CT参数[相对血容量（rbv）、通透性1 （Pm1）、通透性2 (Pm2)]与肿瘤诱导血管生成的组织病理学标志物[微血管密度（MVD）、血管内皮生长因子（VEGF）]的相关性。结果成功建立了对比度增强模型，数学模拟的溶液曲线与测量的时间-密度曲线具有相似性。MVD分级与Pm1呈显著线性相关（r=0.841, p=0.001）， VEGF分级与Pm2呈显著线性相关（r=0.804, 0.005）。结论CT功能成像可作为评价肿瘤血管生成的有效工具

ObjectivesTo establish functional computed tomography (CT) imaging as a method for assessing tumor-induced angiogenesis.Materials and MethodsFunctional CT imaging was performed for 14 renal cell carcinomas with a 4-channel multidetector-row CT system. Functional CT imaging was mathematically analyzed by means of two-compartmental modeling of contrast medium using a computational discretization approach. The model incorporated diffusible kinetics of contrast medium including leakage from the capillary to the extravascular compartment and buck-flux from the extravascular to the capillary compartment. The correlations between functional CT parameters [relative blood volume (rbv), permeability 1 (Pm1), and permeability 2 (Pm2)] and histopathological markers of tumor-induced angiogenesis [microvessel density (MVD) and vascular endothelial growth factor (VEGF)] were statistically analyzed.ResultsThe modeling of contrast enhancement was successfully performed, showing similarity between the mathematically-simulated solution curve and the measured time-density curve. There were significant linear correlations between MVD grade and Pm1 (r=0.841, p=0.001), and between VEGF grade and Pm2 (r=0.804, 0.005) by Pearson's correlations coefficient. ConclusionFunctional CT imaging may be a useful tool toward the assessment of tumor-induced angiogenesis