对比剂稳态磁化率MR成像动态观察大鼠C6胶质瘤血管生成

摘要

Objective To observe changes of the structure and function of microvessels during the formation and development of the rat cerebral glioma with steady-state susceptibility contrast-enhanced MR imaging. Methods A total of 30 bearing-tumor rats were divided into 3 groups (1-week group, 2-week group and 3-week group) and underwent MR examination. Blood volime (BV) and vessel size index (VSI_(MRI)) of peripheral tumor areas, central tumor areas and normal cerebral tissue in the opposite side were measured, and compared with histologic findings. Results With time of bearing-tumor increasing, BV of central tumor area present an up-and-down curve-like change, which related to the host blood vessel regression in tumor central area, the decreasing of blood vessel density and histopathologically obvious necrosis. BV of peripheral tumor areas increased because of active blood angiogenesis in this area, while VSI_(MRI) increased gradually, especially in the central tumor area. There was obviously correlation between the VSI_(MRI) and VSI _(histo) (P<0.01). Conclusion BV and VSI_(MRI) can exactly reflect the morphology and functional information of microcirculation of tumor during the growth and development of gliomas.%目的 使用对比剂稳态磁化率MR成像技术观察不同时间段大鼠C6胶质瘤血管生成过程中微血管结构和功能变化.方法 30只荷瘤大鼠按种植周数分成1、2、3周组,分别行对比剂稳态磁化率对比MR成像,测量肿瘤周边区、中央区及对侧相应正常脑实质区的BV和VSI_(MRI)值,并与病理结果对照.结果 随种植周数增加,肿瘤中心区的BV先升后降,与组织学上肿瘤中央区宿主血管退缩、血管密度下降及出现明显坏死区有关;周边区BV持续上升,与周边区具有活跃的血管生成有关;肿瘤中心区及周边区的VSIMRI值均逐渐增大,以中心区增大更为明显,且同时间段比较二者之间差异有统计学意义.相同时间段、相同ROI内MR与组织学测量的VSI均明显相关(P<0.01).结论 对比剂稳态磁化率MR成像所测量的BV和VSI_(MRI)值能准确地反映胶质瘤生长、发展过程中微血管生成的形态学和功能学信息.