Grøvik Endre, Bjørnerud Atle, Storås Tryggve H, Gjesdal Kjell-Inge
Oslo University Hospital, The Intervention Centre, Oslo, Norway.; University of Oslo, Oslo, Norway.
J Magn Reson Imaging. 2014 Mar;39(3):673-82. doi: 10.1002/jmri.24206. Epub 2013 Aug 1.
To test the feasibility of a novel "split dynamic" method in which high temporal and high spatial resolution dynamic MR images are acquired during a single bolus injection.
High temporal resolution images were acquired using a three-dimensional (3D) dual-echo EPI sequence. The high spatial resolution images were acquired using a 3D T1 -weighted turbo field echo sequence. Simulations were performed to test the split dynamic method in terms of accuracy relative to a continuous acquisition and for temporal sampling requirements for accurate estimation of kinetic parameters. The method was tested in four patients where pharmacokinetic parameters were extracted from the high temporal resolution data.
The split dynamic method enabled quantitative evaluation of both T1- and T2*-weighted characteristics. Simulations showed that splitting the dynamic acquisition does not significantly influence the reliability of parameter estimations. Simulation showed a required temporal resolution of 13, 16, and 8 s for accurate estimates of Ktrans, ve, and vp, respectively, and an optimal sampling interval between 2 and 6 s for peak R2*.
The split dynamic sequence enabled detailed assessment of dynamic T1- and T2*-weighted contrast kinetics without compromising guidelines concerning spatial resolution.
测试一种新型“分割动态”方法的可行性，该方法在单次团注注射期间采集高时间分辨率和高空间分辨率的动态磁共振图像。
使用三维（3D）双回波EPI序列采集高时间分辨率图像。使用3D T1加权涡轮场回波序列采集高空间分辨率图像。进行模拟以测试分割动态方法相对于连续采集的准确性以及准确估计动力学参数的时间采样要求。该方法在4名患者中进行了测试，从高时间分辨率数据中提取药代动力学参数。
分割动态方法能够对T1加权和T2加权特征进行定量评估。模拟表明，分割动态采集不会显著影响参数估计的可靠性。模拟显示，分别准确估计Ktrans、ve和vp所需的时间分辨率为13、16和8秒，R2峰值的最佳采样间隔为2至6秒。
分割动态序列能够在不影响空间分辨率准则的情况下，详细评估动态T1加权和T2*加权对比动力学。
