Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Magn Reson Med. 2010 Mar;63(3):811-6. doi: 10.1002/mrm.22171.
We investigated the influence of the temporal resolution of dynamic contrast-enhanced MRI data on pharmacokinetic parameter estimation. Dynamic Gd-DTPA (Gadolinium-diethylene triamine pentaacetic acid) enhanced MRI data of implanted prostate tumors on rat hind limb were acquired at 4.7 T, with a temporal resolution of approximately 5 sec. The data were subsequently downsampled to temporal resolutions in the range of 15 sec to 85 sec, using a strategy that involves a recombination of k-space data. A basic two-compartment model was fit to the contrast agent uptake curves. The results demonstrated that as temporal resolution decreases, the volume transfer constant (K(trans)) is progressively underestimated (approximately 4% to approximately 25%), and the fractional extravascular extracellular space (v(e)) is progressively overestimated (approximately 1% to approximately 10%). The proposed downsampling strategy simulates the influence of temporal resolution more realistically than simply downsampling by removing samples.
我们研究了动态对比增强 MRI 数据的时间分辨率对药代动力学参数估计的影响。在 4.7T 下，对大鼠后肢植入的前列腺肿瘤进行了动态 Gd-DTPA（钆二乙烯三胺五乙酸）增强 MRI 数据采集，时间分辨率约为 5 秒。随后，使用涉及 k 空间数据重组的策略，将数据下采样到 15 秒至 85 秒的时间分辨率范围内。基本的两室模型拟合到对比剂摄取曲线。结果表明，随着时间分辨率的降低，体积转移常数（K(trans)）逐渐被低估（约 4%至约 25%），并且血管外细胞外空间分数（v(e)）逐渐被高估（约 1%至约 10%）。与简单地通过删除样本进行下采样相比，所提出的下采样策略更真实地模拟了时间分辨率的影响。
