Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University Manchester, Manchester, UK.
Magn Reson Med. 2010 Aug;64(2):595-603. doi: 10.1002/mrm.22430.
The purpose of this study was to determine the impact of water exchange on tracer kinetic parameter estimates derived from T(1)-weighted dynamic contrast-enhanced (DCE)-MRI data using a direct quantitative comparison with DCE-CT. Data were acquired from 12 patients with bladder cancer who underwent DCE-CT followed by DCE-MRI within a week. A two-compartment tracer kinetic model was fitted to the CT data, and two versions of the same model with modifications to account for the fast exchange and no exchange limits of water exchange were fitted to the MR data. The two-compartment tracer kinetic model provided estimates of the fractional plasma volume (v(p)), the extravascular extracellular space fraction (v(e)), plasma perfusion (F(p)), and the microvascular permeability surface area product. Our findings suggest that DCE-CT is an appropriate reference for DCE-MRI in bladder cancers as the only significant difference found between CT and MR parameter estimates were the no exchange limit estimates of v(p) (P = 0.002). These results suggest that although water exchange between the intracellular and extravascular-extracellular space has a negligible effect on DCE-MRI, vascular-extravascular-extracellular space water exchange may be more important.
本研究旨在通过与 DCE-CT 的直接定量比较，确定水交换对 T1 加权动态对比增强（DCE）-MRI 数据得出的示踪动力学参数估计的影响。该研究纳入了 12 例膀胱癌患者，这些患者在一周内接受了 DCE-CT 和 DCE-MRI 检查。将双室示踪动力学模型拟合到 CT 数据中，并对相同的模型进行了两种修改版本，以考虑水交换的快速交换和无交换限制，将其拟合到 MR 数据中。双室示踪动力学模型提供了血浆容积分数（v(p)）、血管外细胞外空间分数（v(e)）、血浆灌注（F(p)）和微血管通透性表面积乘积的估计值。我们的研究结果表明，DCE-CT 是膀胱癌 DCE-MRI 的合适参考，因为在 CT 和 MR 参数估计之间发现的唯一显著差异是 v(p)的无交换限制估计（P=0.002）。这些结果表明，尽管细胞内和血管外细胞外空间之间的水交换对 DCE-MRI 的影响可以忽略不计，但血管-细胞外细胞外空间水交换可能更为重要。
