Department of Mathematics & Statistics, Indian Institute of Technology Kanpur, India.
J Magn Reson Imaging. 2013 Sep;38(3):677-88. doi: 10.1002/jmri.24021. Epub 2013 Feb 6.
To modify the generalized tracer kinetic model (GTKM) by introducing an additional tissue uptake leakage compartment in extracellular extravascular space (LTKM). In addition, an implicit determination of voxel-wise local arterial input function (AIF) Cp (t) was performed to see whether these changes help in better discrimination between low- and high-grade glioma using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).
The modified model (LTKM) was explored and fitted to the concentration-time curve C(t) of each voxel, in which the local AIF Cp (t) could be estimated by a time invariant convolution approximation based on a separately measured global AIF Ca (t). A comparative study of tracer kinetic analysis was performed on 184 glioma patients using DCE-MRI data on 1.5T and 3T MRI systems.
The LTKM analysis provided more accurate pharmacokinetic parameters as evidenced by their relative constancy with respect to the length of concentration-time curve used. In addition, LTKM with local AIF resulted in improved discrimination between low-grade and high-grade gliomas.
LTKM with local AIF provides more accurate estimation of physiological parameters and improves discrimination between low-grade and high-grade gliomas as compared with GTKM.
通过在细胞外细胞外空间（LTKM）中引入额外的组织摄取渗漏隔室来修改广义示踪剂动力学模型（GTKM）。此外，还进行了体素内局部动脉输入函数（AIF）Cp（t）的隐式确定，以观察这些变化是否有助于使用动态对比增强（DCE）磁共振成像（MRI）更好地区分低级别和高级别胶质瘤。
探索并拟合了每个体素的浓度时间曲线 C（t）的修正模型（LTKM），其中局部 AIF Cp（t）可以通过基于单独测量的全局 AIF Ca（t）的时间不变卷积近似来估计。在 1.5T 和 3T MRI 系统上对 184 例胶质瘤患者的 DCE-MRI 数据进行了示踪动力学分析的比较研究。
LTKM 分析提供了更准确的药代动力学参数，这证明了它们相对于使用的浓度时间曲线的长度的相对稳定性。此外，具有局部 AIF 的 LTKM 可改善低级别和高级别胶质瘤之间的区分。
与 GTKM 相比，具有局部 AIF 的 LTKM 可更准确地估计生理参数，并改善低级别和高级别胶质瘤之间的区分。
