Livne Michelle, Madai Vince I, Brunecker Peter, Zaro-Weber Olivier, Moeller-Hartmann Walter, Heiss Wolf-Dieter, Mouridsen Kim, Sobesky Jan
Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany.
Max-Planck-Institute for Neurological Research, Cologne, Germany.
J Neuroimaging. 2017 Sep;27(5):486-492. doi: 10.1111/jon.12428. Epub 2017 Feb 16.
In acute stroke, arterial-input-function (AIF) determination is essential for obtaining perfusion estimates with dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging (DSC-MRI). Standard DSC-MRI postprocessing applies single AIF selection, ie, global AIF. Physiological considerations, however, suggest that a multiple AIFs selection method would improve perfusion estimates to detect penumbral flow. In this study, we developed a framework based on comparable DSC-MRI and positron emission tomography (PET) images to compare the two AIF selection approaches and assess their performance in penumbral flow detection in acute stroke.
In a retrospective analysis of 17 sub(acute) stroke patients with consecutive MRI and PET scans, voxel-wise optimized AIFs were calculated based on the kinetic model as derived from both imaging modalities. Perfusion maps were calculated based on the optimized-AIF using two methodologies: (1) Global AIF and (2) multiple AIFs as identified by cluster analysis. Performance of penumbral-flow detection was tested by receiver-operating characteristics (ROC) curve analysis, ie, the area under the curve (AUC).
Large variation of optimized AIFs across brain voxels demonstrated that there is no optimal single AIF. Subsequently, the multiple-AIF method (AUC range over all maps: .82-.90) outperformed the global AIF methodology (AUC .72-.85) significantly.
We provide PET imaging-based evidence that a multiple AIF methodology is beneficial for penumbral flow detection in comparison with the standard global AIF methodology in acute stroke.
在急性卒中中，动脉输入函数（AIF）的确定对于通过动态磁敏感加权对比增强磁共振成像（DSC-MRI）获得灌注估计值至关重要。标准的DSC-MRI后处理采用单一AIF选择，即全局AIF。然而，从生理学角度考虑，多AIF选择方法可能会改善灌注估计值，以检测半暗带血流。在本研究中，我们开发了一个基于可比的DSC-MRI和正电子发射断层扫描（PET）图像的框架，以比较两种AIF选择方法，并评估它们在急性卒中半暗带血流检测中的性能。
在对17例连续进行MRI和PET扫描的亚急性卒中患者的回顾性分析中，基于两种成像方式得出的动力学模型，逐体素计算优化的AIF。使用两种方法基于优化后的AIF计算灌注图：（1）全局AIF和（2）通过聚类分析确定的多个AIF。通过受试者操作特征（ROC）曲线分析，即曲线下面积（AUC），测试半暗带血流检测的性能。
全脑体素优化AIF的差异很大，表明不存在最佳单一AIF。随后，多AIF方法（所有图的AUC范围：0.82 - 0.90）显著优于全局AIF方法（AUC 0.72 - 0.85）。
我们提供了基于PET成像的证据，表明与急性卒中标准全局AIF方法相比，多AIF方法有利于半暗带血流检测。
