Effect of T2* correction on contrast kinetic model analysis using a reference tissue arterial input function at 7 T.
Effect of T2* correction on contrast kinetic model analysis using a reference tissue arterial input function at 7 T.
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DOI：
10.1007/s10334-015-0496-1
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发表时间：
2015-12
期刊：
影响因子：
--
通讯作者：
Kim SG
中科院分区：
文献类型：
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作者：
Zhang J;Freed M;Winters K;Kim SG
研究当使用参考组织动脉输入函数（AIF）时，T2*校正对从t1加权动态对比增强（DCE） MRI数据估计动力学参数的影响。采用双梯度回波序列在7T处获取7只4T1小鼠乳腺肿瘤的DCE-MRI数据。AIF是从肌肉感兴趣的区域估计出来的。采用扩展Tofts模型估计肿瘤增强部分的药代动力学参数，并对病变和AIF进行T2*校正。假设AIF和病变时间-强度曲线经T2*校正后得到的参数为参考标准。在全群体中，T2*校正与未校正方法间的传递常数（Ktrans）差异有统计学意义（p<0.05），但间质体积分数（ve）差异无统计学意义（p<0.05）。单独来看，4个和6个肿瘤的Ktrans和ve在T2*校正和未校正方法之间没有显著差异。相比之下，如果不使用T2*校正，在Ktrans中位数大于0.4 min−1的其他肿瘤中，Ktrans明显被低估。在动力学模型分析中，即使从对比剂浓度相对较低的参比组织中估计AIF， T2*对高Ktrans肿瘤的影响也不可忽略。
To investigate the effect of T2* correction on estimation of kinetic parameters from T1-weighted dynamic contrast enhanced (DCE) MRI data when a reference-tissue arterial input function (AIF) is used. DCE-MRI data were acquired from 7 mice with 4T1 mouse mammary tumors using a double gradient echo sequence at 7T. The AIF was estimated from a region of interest in the muscle. The extended Tofts model was used to estimate pharmacokinetic parameters in the enhancing part of the tumor, with and without T2* correction of the lesion and AIF. The parameters estimated with T2* correction of both the AIF and lesion time-intensity curve were assumed to be the reference standard. For the whole population, there was significant difference (p<0.05) in transfer constant (Ktrans) between T2* corrected and not corrected methods, but not in interstitial volume fraction (ve). Individually, no significant differences were found in Ktrans and ve of four and six tumors, respectively, between the T2* corrected and not corrected methods. In contrast, Ktrans was significantly underestimated, if the T2* correction was not used, in other tumors of which median Ktrans was larger than 0.4 min−1. T2* effect on tumors with high Ktrans may not be negligible in kinetic model analysis, even if AIF is estimated from reference tissue where the concentration of contrast agent is relatively low.