基于肿瘤全域MRI信号强度的直方图分析分级诊断脑膜瘤

Grading diagnosis of meningiomas with histogram analysis of MRI based on whole tumor volume measurement

目的探讨基于肿瘤全域的T1WI、T2WI及增强T1WI信号强度直方图对脑膜瘤分级的价值。方法回顾性分析经手术及病理证实的139例Ⅰ级脑膜瘤患者和38例Ⅱ级脑膜瘤患者的术前MRI,采用Omni-Kinetics软件,于轴位T1WI、T2WI及增强T1WI上,在包含肿瘤实质的每层图像上沿肿瘤边缘勾画ROI,将其累加,获得三维ROI的信号强度直方图及其参数,比较Ⅰ级与Ⅱ级脑膜瘤间各参数的差异,并对有差异的参数绘制ROC曲线,评估其分级诊断脑膜瘤的效能。结果基于T1WI信号强度直方图参数中,Ⅱ级脑膜瘤的值域、体积数及标准差高于Ⅰ级,偏度及均匀性低于Ⅰ级(P均<0.05);均匀性诊断Ⅰ级与Ⅱ级脑膜瘤的效能最佳(AUC=0.678,P<0.05),敏感度及特异度分别为62.6%、73.7%。在基于T2WI信号强度直方图参数中,Ⅱ级脑膜瘤的第90、95百分位数、体积数、标准差及方差均高于Ⅰ级,均匀性及峰度低于Ⅰ级(P均<0.05),均匀性诊断Ⅰ级与Ⅱ级脑膜瘤的效能最佳(AUC=0.702,P<0.05),敏感度及特异度分别为56.1%、84.2%。在基于增强T1WI信号强度直方图参数中,Ⅱ级脑膜瘤的最小值、第5、10、25百分位数、峰度及均匀性均低于Ⅰ级,体积数及偏度高于Ⅰ级(P均<0.05);均匀性诊断Ⅰ级与Ⅱ级脑膜瘤的效能最佳(AUC=0.708,P<0.05),敏感度及特异度分别为64.7%、73.7%。结论基于肿瘤全域测量的T1WI、T2WI及增强T1WI信号强度直方图有助于脑膜瘤分级,均匀性是最佳影像学分级诊断指标。

Objective To observe the value of T1 WI,T2 WI and contrasted T1 WI histogram analysis based on whole tumor volume measurement for the classification of meningiomas.Methods Preoperative MRI of 139 patients with pathologically confirmed grade Ⅰ meningioma and 38 patients with grade Ⅱ meningioma were retrospectively analyzed.ROIs covering the entire tumor were drawn in each slice of axial T1 WI,T2 WI and contrasted T1 WI with Omni-Kinetics software.The three-dimensional ROI signal intensity histogram and its parameters were obtained by accumulating all ROIs.All the parameters were compared between two grades,and then ROC curve was constructed to assess the grading diagnostic efficacy of histogram parameters with significant differences between two grades.Results Among the parameters based on T1 WI signal intensity histogram,the range,volume count,standard deviation of gradeⅡ meningioma were higher,while skewness and uniformity were lower than those of gradeⅠtumors（all P〈0.05）;the uniformity was the best parameter for grading diagnosis,with the AUC of 0.678（P〈0.05）,the sensitivity and specificity of 62.6% and73.7%.Among T2 WI parameters,compared with those of grade Ⅰ meningioma,the 90 th percentile,95 th percentile,volume count,standard deviation and variance of grade Ⅱ meningioma increased,while the uniformity and kurtosis decreased（all P〈0.05）,the grading diagnostic ability of uniformity was the best（AUC=0.702,P〈0.05）,with the sensitivity and specificity of 56.1% and 84.2%.Among contrasted T1 WI parameters,the min-intensity,5 th percentile,10 th percentile,25 th percentile,kurtosis and uniformity of grade Ⅱ meningioma were lower,while volume count and skewness were higher than those of grade Ⅰ tumors（all P〈0.05）;the uniformity was the best parameter for grading diagnosis（AUC=0.708,P〈0.05）,with the sensitivity and specificity of 64.7% and 73.7%.Conclusion Histogram analysis of T1 WI,T2 WI and contrasted T1 WI based on the entire tumor volume measurement conduce to the grading of meningiomas,and the uniformity of tumor shows superior diagnostic value of meningiomas.