Investigation and optimization of parameter accuracy in dynamic contrast-enhanced MRI
Investigation and optimization of parameter accuracy in dynamic contrast-enhanced MRI
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DOI：
10.1002/jmri.21489
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发表时间：
2008-09-01
影响因子：
4.4
通讯作者：
Cheng, Hai-Ling Margaret
中科院分区：
文献类型：
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作者：
Cheng, Hai-Ling Margaret
目的：提出一种改进的药代动力学模型，以提高参数准确性，并研究不准确的动脉输入函数（AIF）对动态对比增强（VCE）-MRI参数传递常数（K-trans）估计的影响。血容量（up）和间质体积W。材料和方法：在大范围的生理值上模拟组织摄取曲线，并分析不同的AIF测量误差和时间分辨率。假设AIF测量在推注振幅（快速采样）中不准确或对未知的时间偏移敏感（双指数衰减拟合的慢采样）。结果：修改后的模型充分减少了传输时间效应引起的参数估计误差。AIF推注振幅中的误差导致K-transs和nu（p）中的成反比误差; nu（e）保持稳健。使用双指数AIF获得了K-transs中更一致的误差（约20%低估）。以严重低估为代价。结论：虽然准确。高时间分辨率AIF对于估计向上是必要的。在低时间分辨率下获得的双指数AIF（
Purpose: To present a modified pharmacokinetic model for improved parameter accuracy and to investigate the influence of an inaccurate arterial input function (AIF) on dynamic contrast-enhanced (DCE)-MRI parameter estimates of the transfer constant (K-trans). blood volume (up), and interstitial volume W.Materials and Methods: Tissue uptake curves were simulated over a large range of physiological values and analyzed for different AIF measurement errors and temporal resolutions. The AIF measurement was assumed to be inaccurate in the bolus amplitude (rapid sampling) or susceptible to unknown temporal offsets (slow sampling with biexponential decay fit).Results: The modified model adequately reduces errors in parameter estimates arising from transit time effects. An error in the AIF bolus amplitude results in an inversely proportional error in K-trans and nu(p); nu(e) remains robust. More consistent error in K-trans (approximate to 20% underestimation) was obtained using a biexponential AIF. at the expense of severely underestimating up.Conclusion: While an accurate. high temporal resolution AIF is essential for estimating up. a biexponential AIF acquired at low temporal resolution (