This work describes a comprehensive study of the vascular tree and perfusion characteristics of normal kidney and renal cell carcinoma. Methods: Nephrectomy specimens were perfused ex-vivo, and the regional blood flow was determined by infusion of radioactive microspheres. The vascular architecture was characterized by micronized barium sulphate infusion. Kidneys were subsequently sagitally sectioned, and autoradiograms were obtained to show the perfusate flow in relation to adjacent contact X-ray angiograms. Vascular resistance in defined tissue compartments was quantified, and finally, the tumor vasculature was 3D reconstructed via the micro-CT technique. Results show that the vascular tree of the kidney could be distinctly defined, and autoradiograms disclosed a high cortical flow. The peripheral resistance unit of the whole perfused specimen was 0.78 ± 0.40 (n= 26), while that of the renal cortex was 0.17 ± 0.07 (n= 15 with 114 samples). Micro-CT images from both cortex and medulla defined the vascular architecture. Angiograms from the renal tumors demonstrated a significant vascular heterogeneity within and between different tumors. A dense and irregular capillary network characterized peripheral tumor areas, whereas central parts of the tumors were less vascularized. Despite the dense capillarity, low perfusion through vessels with a diameter below 15 µm was seen on the autoradiograms. We conclude that micronized barium sulphate infusion may be used to demonstrate the vascular architecture in a complex organ. The vascular resistance was low, with little variation in the cortex of the normal kidney. Tumor tissue showed a considerable vascular structural heterogeneity with low perfusion through the peripheral nutritive capillaries and very poor perfusion of the central tumor, indicating intratumoral pressure exceeding the perfusion pressure. The merits and shortcomings of the various techniques used are discussed.
本研究对正常肾脏及肾细胞癌的血管树及灌注特征进行了全面研究。方法：对肾切除标本进行离体灌注，通过放射性微球灌注测定区域血流量。采用硫酸钡微颗粒灌注法表征血管结构。随后对肾脏进行矢状切面处理，获取放射自显影图像以显示灌注血流分布，并与相邻接触式X射线血管造影图像进行关联分析。量化特定组织区域的血管阻力，最终通过显微CT技术对肿瘤血管系统进行三维重建。结果显示：肾脏血管树可清晰界定，放射自显影显示皮质区血流灌注量较高。整体灌注标本的外周阻力单位为0.78±0.40（n=26），而肾皮质区为0.17±0.07（n=15，含114个样本）。皮质与髓质的显微CT图像均清晰呈现血管结构。肾脏肿瘤血管造影显示不同肿瘤内部及肿瘤间存在显著血管异质性：肿瘤周边区域呈现密集而不规则的毛细血管网特征，而肿瘤中央区域血管化程度较低。尽管毛细血管密度较高，但放射自显影显示直径小于15微米的血管灌注量较低。结论：硫酸钡微颗粒灌注法可用于复杂器官的血管结构显影。正常肾皮质血管阻力较低且变异度小。肿瘤组织呈现显著的血管结构异质性，周边营养毛细血管灌注量低，中央肿瘤区域灌注极差，提示瘤内压力超过灌注压力。文中还讨论了各项技术的优势与局限性。
Ex Vivo Vascular Imaging and Perfusion Studies of Normal Kidney and Tumor Vasculature
肿瘤(癌症)患者之家