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Background: Recent development of cancer treatments, scientists have realized the effect of vasculature in choosing the treatment method and drug delivery to the tumor tissue. Therefore, they seek to develop accurate imaging methods of microvessels inside cancer tissues. To prepare such images, a X-ray micro-Computed Tomography (μCT) and a suitable contrast agent are needed. The aim of this research is to compare new techniques for 3D imaging of microvessels network inside cancer tissues. Materials and Methods: By studying the scientific articles of the last two decades, proposed methods to obtain the desired images have been extracted. Advantages, disadvantages and limitations are discussed. Results: Josef Ehling et al. (2014) show that the combination of functional in vivo and anatomical ex vivo μCT allows highly accurate vessel size and vessel branching of blood volume and highly detailed three-dimensional analysis of the vascular network in tumors. This work has been examined in two types of cancer models (A431 & A549). Ruslan Hlushchuk et al. (2018) describe µAngiofil-enhanced μCT-based visualization of vasculature within different cancerous tissues. µAngiofil is a new polymerizing contrast agent for microangioCT imaging of entire vascular networks. The contrast agent homogeneously fills the entire vasculature and remains elastic enough for long term storage in 2% PFA. The additional autofluorescent properties of the contrast agent that allows for histological analysis and correlative microscopy. Conclusion: μCT with µAngiofil is a new efficient tool to study physiological and pathological changes in microvessels inside tumors. This approach has enabled non-destructive 3D imaging of tumor tissue along with its vascular network. One of the disadvantages of this method is that it is performed on tissues outside the body. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases are among the leading causes of death in the world. The coronary blockage is one of most common types of these diseases that in the majority of cases has been treated by bypass surgery. In the bypass surgery, a graft is implemented to alter the blocked coronary and allow the blood supply process. The hemodynamic characteristics of the bypass strongly depend on the geometry and mechanical properties of the graft. In the present study, the fluid-structure interaction (FSI) analysis is conducted to investigate the bypass performance for a thoracic artery as well as a saphenous vein graft. Blood flow introduces a pressure on the walls of the graft which behaves as a hyperelastic material. A complete coronary bypass with stenosis degrees of 70% and 100% is modeled. To consider the nonlinear stress-strain behavior of the grafts, a five parameter Mooney-Rivlin hyperplastic model is implemented for the structural analysis and blood is assumed to behave as a Newtonian fluid. The simulations are performed for a structured grid to solve the governing equations using finite element method (FEM). The results show that wall shear stress (WSS) for saphenous vein is larger than that of thoracic artery while the total deformation of the thoracic artery is larger compared to the saphenous vein. Also, for the venous grafts or lower stenosis degree, the oscillatory shear index (OSI) is higher at both left and right anastomoses meaning that venous grafts as well as lower degree of stenosis are more critical in terms of restenosis. [ABSTRACT FROM AUTHOR]