目的探讨MR灌注加权成像(perfusion weighted imaging,PWI)的局部特征和全脑特征在急性脑卒中血管内治疗后预后中的价值。材料与方法回顾性分析在我院就诊的180例急性脑卒中患者的PWI图像。采用ITK-SNAP软件勾画Tmax图的灌注异常感兴趣...目的探讨MR灌注加权成像(perfusion weighted imaging,PWI)的局部特征和全脑特征在急性脑卒中血管内治疗后预后中的价值。材料与方法回顾性分析在我院就诊的180例急性脑卒中患者的PWI图像。采用ITK-SNAP软件勾画Tmax图的灌注异常感兴趣区,应用SPM软件自动分割Tmax图全脑区。应用AK软件分别提取局部和全脑特征并降维,通过支持向量机分类器构建急性脑卒中预后模型并寻找最优预测模型。结果经最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)降维后与预后最相关的局部特征为6个、全脑特征为5个、联合局部和全脑的特征为10个。受试者工作特征(receiver operating characteristic,ROC)曲线分析结果显示基于局部和全脑特征构建的急性脑卒中预后预测模型的曲线下面积(area under the curve,AUC)为0.900,敏感度和特异度分别为82.3%、89.1%,明显优于局部特征模型(AUC=0.706;Z=-3.248;P=0.001)和全脑特征模型(AUC=0.711;Z=-3.393;P<0.001)。结论联合局部和全脑的PWI特征可更为准确地预测急性脑卒中患者预后,为临床早期干预提供个性化指导。展开更多
Isotopic abundance ratios in chemical exchange separation sample were determined using GV IsoProbe multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). GV IsoProbe MC-ICP-MS was calibrated by the l...Isotopic abundance ratios in chemical exchange separation sample were determined using GV IsoProbe multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). GV IsoProbe MC-ICP-MS was calibrated by the lithium nature isotope reference material. Calibrated GV IsoProbe MC-ICP-MS was used to determine lithium isotope abundance ratio which was produced through chemical change separation.展开更多
文摘目的探讨MR灌注加权成像(perfusion weighted imaging,PWI)的局部特征和全脑特征在急性脑卒中血管内治疗后预后中的价值。材料与方法回顾性分析在我院就诊的180例急性脑卒中患者的PWI图像。采用ITK-SNAP软件勾画Tmax图的灌注异常感兴趣区,应用SPM软件自动分割Tmax图全脑区。应用AK软件分别提取局部和全脑特征并降维,通过支持向量机分类器构建急性脑卒中预后模型并寻找最优预测模型。结果经最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)降维后与预后最相关的局部特征为6个、全脑特征为5个、联合局部和全脑的特征为10个。受试者工作特征(receiver operating characteristic,ROC)曲线分析结果显示基于局部和全脑特征构建的急性脑卒中预后预测模型的曲线下面积(area under the curve,AUC)为0.900,敏感度和特异度分别为82.3%、89.1%,明显优于局部特征模型(AUC=0.706;Z=-3.248;P=0.001)和全脑特征模型(AUC=0.711;Z=-3.393;P<0.001)。结论联合局部和全脑的PWI特征可更为准确地预测急性脑卒中患者预后,为临床早期干预提供个性化指导。
文摘Isotopic abundance ratios in chemical exchange separation sample were determined using GV IsoProbe multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). GV IsoProbe MC-ICP-MS was calibrated by the lithium nature isotope reference material. Calibrated GV IsoProbe MC-ICP-MS was used to determine lithium isotope abundance ratio which was produced through chemical change separation.
