摘要
目的观察兔肝VX2种植瘤三维适形放疗(3DCRT)前、后MR成像特点和灌注参数的变化。方法新西兰大白兔30只,采用组织块种植法制成兔肝VX2模型,随机分为治疗组和对照组,2周后治疗组兔接受3DCRT治疗,单次放疗剂量20Gy。于放疗前、后10d分别对两组行磁共振灌注加权成像(PWI)及增强扫描。选取肿瘤中央区、周边区和瘤周正常肝组织的感兴趣区(ROI),分别测量血流灌注值,进行统计学分析。PWI采用信号强度-时间曲线的最大信号下降斜率(SRSmax)作为定量指标,分析不同ROI的SRSmax下降程度及其规律。结果23只荷瘤兔纳入研究,其中治疗组12只,对照组11只。治疗组放疗后肿瘤中央区及瘤周区SRSmax值均较放疗前降低(P<0.05);对照组前后两次扫描中肿瘤中央区及瘤周区SRSmax值差异无统计学意义(P>0.05)。结论PWI能反映VX2种植瘤放疗后微循环及血流动力学变化。SRSmax可作为活体评价肿瘤微血管的指标。
Objective To observe changes of perfusion-weighted imaging （PWI） parameters before and after three-dimensional conformal radiotherapy （3DCRT） of rabbit models of hepatic VX2 tumors. Methods Thirty New Zealand rabbits were implanted with VX2 tumor in liver by tissue block and divided randomly into treatment group and control group （each n = 15）. Contrast-enhanced MR PWI scan were performed 10 days before and after 3DCRT for the two groups. ROIs of the VX2 tumor center, tumor border and paratumor liver parenchyma were selected and blood perfusion values were measured, respectively, and quantitative variable maximal signal reduction slope （SRSmax） of the signal intensity-time curves were created. Results Model of hepatic VX2 tumors was successfully established on 30 rabbits, and finally 23 rabbits were enrolled （12 in the treatment group and 11 in the control group）. The SRSmax of tumor center and tumor border of treatment group after 3DCRT were lower than that before （P〈0. 05）, whereas no statistical significance of the SRSmax of tumor center nor tumor border was found in the control group （P〉0. 05）. Conclusion PWI can reflect the microcirculative and hemodynamic changes of rabbit models of hepatic VX2 tumors after 3DCRT. SRSmax can be used as a live indicator of evaluating tumor microvascular.
出处
《中国医学影像技术》
CSCD
北大核心
2009年第4期543-546,共4页
Chinese Journal of Medical Imaging Technology
基金
广东省科技厅基金(2004B36001043)
关键词
癌
肝细胞
磁共振成像
灌注
模型
动物
Carcinoma, hepatoeellular
Magnetic resonance imaging
Perfusion
Models, animal
