Department of the Imaging, University Hospital Pilsen and Charles University Medical Faculty in Pilsen, Czech Republic.
Department of the Imaging, University Hospital Pilsen and Charles University Medical Faculty in Pilsen, Czech Republic; Klinik für Radiologie und Nuklearmedizin, Universitäts Klinikum Mannheim.
Eur J Radiol. 2023 Jun;163:110797. doi: 10.1016/j.ejrad.2023.110797. Epub 2023 Mar 24.
Angiogenesis in healthy tissue and within malignant tumors differs on many levels, which may partly be explained by vascular mimicry formation resulting in altered contrast material or different radiopharmaceuticals distributions. Failed remodulation results in changes in the molecular exchange through the capillary wall and those consequences affect the behavior of contrast agents and radiopharmaceuticals. One of the most indicative signs of malignant tissue is the increased permeability and the faster molecular exchange that occurs between the extracellular and intravascular spaces. Dynamic imaging can help to assess the changed microenvironment. The fast-distribution of molecules reflects newly developed conditions in blood-flow redistribution inside a tumor and within the affected organ during the early stages of tumor formation. Tumor development, as well as aggressiveness, can be assessed based on the change to the vascular bed development, the level of molecular exchange within the tissue, and/or indicative distribution within the organ. The study of the vascular network organization and its impact on the distribution of molecules is important to our understanding of the image pattern in several imaging methods, which in turn influences our interpretation of the findings. A hybrid imaging approach (including PET/MRI) allows the quantification of vascularization and/or its pathophysiological impressions in structural and metabolic images. It might optimize the evaluation of the pretreatment imaging, as well as help assess the effect of therapy targeting neovascularization; antiVEGF drugs and embolization-based therapies, for example.
健康组织和恶性肿瘤中的血管生成在多个层面上存在差异，这部分可以通过血管模拟形成来解释，导致对比剂或不同放射性药物分布的改变。重塑失败导致通过毛细血管壁的分子交换发生变化，这些后果会影响对比剂和放射性药物的行为。恶性组织最具指示性的特征之一是细胞外和血管内空间之间发生的通透性增加和更快的分子交换。动态成像有助于评估微环境的变化。分子的快速分布反映了在肿瘤形成的早期阶段，肿瘤内和受影响器官内血流重新分布的新情况。可以根据血管床发育、组织内分子交换水平和/或器官内的指示性分布的变化来评估肿瘤的发展和侵袭性。研究血管网络的组织及其对分子分布的影响对于我们理解几种成像方法中的图像模式很重要，这反过来又影响我们对研究结果的解释。杂交成像方法（包括 PET/MRI）允许定量评估血管化及其在结构和代谢图像中的病理生理影响。它可能优化预处理成像的评估，并有助于评估针对新生血管化的治疗效果；例如，抗 VEGF 药物和基于栓塞的治疗。
