基于光谱CT的腹部实质器官碘浓度测量的可重复性分析

Reproducibility Analysis of Iodine Concentrations of Abdominal Parenchymal Organs Based on Spectral CT

目的探讨基于光谱CT的腹部实质器官碘浓度测量的可重复性。方法回顾性分析50例行腹部光谱CT增强患者的静脉期无水碘图图像,测量肝左叶、肝右叶、肝尾状叶、脾脏、胰腺及双肾皮质碘浓度,采用组内相关系数(ICC)分析及Bland-Altman法进行观察者内及观察者间可重复性分析。结果观察者内肝左叶、肝右叶、肝尾状叶、脾脏、胰腺、左肾及右肾的ICC值分别为0.938(0.894,0.965)、0.932(0.884,0.961)、0.939(0.895,0.965)、0.947(0.909,0.970)、0.912(0.851,0.949)、0.946(0.906,0.969)及0.907(0.842,0.946),可重复性等级均为优;观察者间ICC值分别为0.947(0.909,0.970)、0.927(0.875,0.958)、0.943(0.902,0.968)、0.956(0.924,0.975)、0.934(0.887,0.962)、0.927(0.875,0.958)及0.892(0.818,0.937),可重复性等级均为优。Bland-Altman法分析提示观察者内肝尾状叶、脾脏、胰腺及双肾两次测量差值点均超过95%位于一致性界限内,观察者间肝尾状叶、脾脏及右肾两次测量差值点均超过95%位于一致性界限内。结论基于光谱CT的肝尾状叶及脾脏碘浓度测量具有稳健的可重复性。

Objective To investigate the intra-and inter-observer reproducibility of iodine concentrations of abdominal parenchymal organs based on spectral CT.Methods The water-free iodine images of the venous phase were retrospectively obtained from 50 patients with abdominal dynamic spectral CT scans.The iodine concentrations were measured in the left,right and caudate lobes of liver,spleen,pancreas and bilateral kidneys.Intraclass correlation coefficient(ICC)and Bland-Altman plot were employed to analyze the intra-and inter-observer reproducibility.Results The intra-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.938(0.894,0.965),0.932(0.884,0.961),0.939(0.895,0.965),0.947(0.909,0.970),0.912(0.851,0.949),0.946(0.906,0.969)and 0.907(0.842,0.946),which indicated good intra-observer reproducibility.The inter-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.947(0.909,0.970),0.927(0.875,0.958),0.943(0.902,0.968),0.956(0.924,0.975),0.934(0.887,0.962),0.927(0.875,0.958)and 0.892(0.818,0.937),which indicated good inter-observer reproducibility.Bland-Altman plots presented that more than 95%points of the intra-observer differences located within 95%CI of limits of agreement for the caudate lobe of liver,spleen,pancreas and bilateral kidneys,which was same as inter-observer differences of the caudate lobe of liver,spleen and right kidney.Conclusion The iodine concentration measurement based on the spectral CT presented good intra-and inter-observer reproducibility for the caudate lobe of liver and spleen.