Department of Radiology, The University of Chicago, Chicago, IL 60637, USA.
Phys Med. 2010 Apr;26(2):111-6. doi: 10.1016/j.ejmp.2009.07.001. Epub 2009 Aug 3.
The purpose of this research was to test whether dynamic contrast enhanced MRI could assess the effect of green tea on the angiogenic properties of transplanted rodent tumors. Copenhagen rats bearing AT6.1 prostate tumors inoculated in the hind limbs were randomly assigned to cages in which they were allowed to only drink either plain water (control group) or water containing green tea extract (treated group). Assignments were made after a baseline MRI experiment (week 0) was performed on each rat at 4.7T. All the rats were subsequently imaged at day 7 (week 1) and day 14 (week 2) to follow tumor growth and vascular development. The two-compartment pharmacokinetic model was used to analyze the dynamic contrast Gd-DTPA enhanced MRI data on a pixel-by-pixel basis over the tumor area to obtain the volume transfer constant (K(trans)) and extravascular extracellular space (v(e)). An identity Chi-squared test showed that the distributions of averaged histograms (n=6) of K(trans) and v(e) were significantly different from week 0 to both weeks 1 and 2 (p<0.001) in both the control and the treated rats due to increasing areas of tumor necrosis. However, the tumor growth rate was statistically indistinguishable between control and treated rats. There was no significant difference in the distributions of K(trans) and v(e) between control and treated rats. The results showed that no effects of green tea on tumor micro-vasculature were measurable by dynamic Gd-DTPA enhanced MRI.
本研究旨在测试动态对比增强 MRI 是否可用于评估绿茶对移植啮齿动物肿瘤血管生成特性的影响。在腿部接种 AT6.1 前列腺肿瘤的哥本哈根大鼠被随机分配到笼中，允许它们仅饮用普通水（对照组）或含绿茶提取物的水（治疗组）。在每只大鼠的 4.7T 进行基线 MRI 实验（第 0 周）后进行分配。所有大鼠随后在第 7 天（第 1 周）和第 14 天（第 2 周）进行成像，以跟踪肿瘤生长和血管发育。使用两室药代动力学模型对肿瘤区域的动态对比 Gd-DTPA 增强 MRI 数据进行逐像素分析，以获得体积转移常数（K(trans)) 和血管外细胞外空间（v(e))。由于肿瘤坏死面积增加，身份卡方检验显示 K(trans)和 v(e)的平均直方图分布（n=6）从第 0 周到第 1 周和第 2 周均与第 0 周有显著差异（p<0.001）。在对照组和治疗组大鼠中。然而，肿瘤生长速率在对照组和治疗组大鼠之间无统计学差异。在对照组和治疗组大鼠之间，K(trans)和 v(e)的分布无显著差异。结果表明，动态 Gd-DTPA 增强 MRI 无法测量绿茶对肿瘤微血管的影响。
