Aerts H J W L, van Riel N A W, Backes W H
Control Systems Group, Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
Magn Reson Med. 2008 May;59(5):1111-9. doi: 10.1002/mrm.21575.
Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory and computer simulations, the confounding effects of volume, rate and multiplicity of a contrast injection on the reliability of K(trans) estimation was assessed. A new tracer-distribution model (TDM), based on in vivo data from rectal cancer patients, served to describe the relationship between the contrast agent injection and the blood time-course. A pharmacokinetic model (PKM) was used to describe the relation between the blood and tumor tissue time-courses. By means of TDM and PKM in series, the tissue-transfer function of the PKM was analyzed. As both the TDM and PKM represented low-frequency-pass filters, the energy-density at low frequencies of the blood and tissue time-courses was larger than at high frequencies. The simulations, based on measurements in humans, predict that the K(trans) is most reliable with a high injection volume administered in a single injection, where high rates only modestly improve K(trans).
动态对比增强磁共振成像（DCE-MRI）实验设置的优化，如对比剂给药方案，对于可靠量化微循环特性（如容积转移常数K(trans)）非常重要。利用系统辨识理论和计算机模拟，评估了对比剂注射的体积、速率和次数对K(trans)估计可靠性的混杂影响。基于直肠癌患者的体内数据建立了一种新的示踪剂分布模型（TDM），用于描述对比剂注射与血液时程之间的关系。采用药代动力学模型（PKM）描述血液和肿瘤组织时程之间的关系。通过串联TDM和PKM，分析了PKM的组织传递函数。由于TDM和PKM均为低频通滤波器，血液和组织时程的低频能量密度高于高频。基于人体测量的模拟预测，单次注射高注射量时K(trans)最可靠，高注射速率仅适度提高K(trans)。
