The goal of this paper is to investigate the validity of a hybrid embedded/homogenized in-silico approach for modeling perfusion through solid tumors. The rationale behind this novel idea is that only the larger blood vessels have to be explicitly resolved while the smaller scales of the vasculature are homogenized. As opposed to typical discrete or fully-resolved 1D-3D models, the required data can be obtained with in-vivo imaging techniques since the morphology of the smaller vessels is not necessary. By contrast, the larger vessels, whose topology and structure is attainable non-invasively, are resolved and embedded as one-dimensional inclusions into the three-dimensional tissue domain which is modeled as a porous medium. A sound mortar-type formulation is employed to couple the two representations of the vasculature. We validate the hybrid model and optimize its parameters by comparing its results to a corresponding fully-resolved model based on several well-defined metrics. These tests are performed on a complex data set of three different tumor types with heterogeneous vascular architectures. The correspondence of the hybrid model in terms of mean representative elementary volume blood and interstitial fluid pressures is excellent with relative errors of less than 4%. Larger, but less important and explicable errors are present in terms of blood flow in the smaller, homogenized vessels. We finally discuss and demonstrate how the hybrid model can be further improved to apply it for studies on tumor perfusion and the efficacy of drug delivery.
翻译:本文的目的是调查通过固态肿瘤建模渗入的混合嵌入/混合硅基内方法的有效性。 这个新想法背后的理由是,只有较大的血管容器必须明确解决,而血管模型的较小比例则要同质化。相对于典型的离散或完全溶解的1D-3D模型,所需要的数据可以用静脉成像技术获得,因为不需要小船只的形态学来进行。相比之下,较大的船只,其表层和结构可以非侵入性地实现,已经解决,并嵌入三维组织域的一维效率。只有较大的血管容器才需要明确解决,而血管模型的较小比例则是同异质的。我们验证混合模型并优化其参数,将其结果与基于若干明确界定的模型的完全解析模型进行对比。这些测试可以使用由三种不同肿瘤类型组成的复杂数据集进行进一步改进,其表层和结构可以作为一维度纳入三维组织域内,而三维组织域内则以多孔介质介质为介质。 一种健全的迫击炮型模型的对应性模型,其真实性比普通的流压值要低得多,其次的血液体体体积比重的体积的模型,其目前的体型模型和流压值比重的体积要小。 我们的体型模型的体型模型的体型模型的体型模型的体型号的体型号的体型号的体型体型号的体型号的体型和体型号的体型号的体型号的体型体型号的体型号的体型号的体型号的体型体型号的体型号的体型号的体型号的体型号的体型体型号的体型号比号比号比号的体型号的体型号的体型体型号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比号比体型体型号的体型体型号比体型号的体型号比体型号比体型号的体型体型号的体型号的体型号比体型号的体型号比体型号比体型号比号的体型号比体型号的体型体型号