Yankeelov Thomas E, DeBusk Laura M, Billheimer D Dean, Luci Jeffrey J, Lin P Charles, Price Ronald R, Gore John C
Institute of Imaging Science, and Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37232-2310, USA.
J Magn Reson Imaging. 2006 Nov;24(5):1140-7. doi: 10.1002/jmri.20729.
To test the repeatability of a reference region (RR) model for the analysis of dynamic contrast-enhanced MRI (DCE-MRI) in a mouse model of cancer at high field.
Seven mice were injected with 10(6) 4T1 mammary carcinoma cells and imaged eight to 10 days later on a Varian 7.0T scanner. Two DCE-MRI studies were performed for each mouse (separated by 2.5 hours). The RR model was used to analyze the data, and returned estimates on the perfusion-permeability index (Ktrans) for the RR and the tissue of interest (TOI), as well as the extravascular extracellular volume fraction (ve) for the TOI.
When the first injection was compared with the second injection, all parameters tested were highly correlated (r2=0.90, 0.62, 0.82 for the RR Ktrans, TOI Ktrans, and TOI ve, respectively, with P<0.001 for all). To observe a statistically significant change (at the 5% level) in a treatment study with seven animals in each group, log10 changes of 0.084 and 0.077 in the tumor Ktrans and ve, respectively, are required.
If a reliable arterial input function (AIF) is unavailable, the RR model is a reasonable alternative to measuring MRI contrast-agent (CA) kinetics in mouse models of cancer at high field.
在高场强小鼠癌症模型中测试用于分析动态对比增强磁共振成像（DCE-MRI）的参考区域（RR）模型的可重复性。
给7只小鼠注射10(6)个4T1乳腺癌细胞，8至10天后在瓦里安7.0T扫描仪上成像。对每只小鼠进行两项DCE-MRI研究（间隔2.5小时）。使用RR模型分析数据，并得出RR和感兴趣组织（TOI）的灌注-渗透指数（Ktrans）以及TOI的血管外细胞外体积分数（ve）的估计值。
将第一次注射与第二次注射进行比较时，所有测试参数均具有高度相关性（RR的Ktrans、TOI的Ktrans和TOI的ve的r2分别为0.90、0.62和0.82，所有P均<0.001）。在每组有7只动物的治疗研究中，要观察到统计学上的显著变化（5%水平），肿瘤Ktrans和ve的log10变化分别需要0.084和0.077。
如果没有可靠的动脉输入函数（AIF），RR模型是在高场强小鼠癌症模型中测量MRI造影剂（CA）动力学的合理替代方法。
