增强T1WI直方图在胶质母细胞瘤和脑单发转移瘤鉴别诊断中的应用

Post Contrast-enhanced T1WI Histogram Analysis for Differentiating Glioblastom from Solitary Brain Metastasis

目的胶质母细胞瘤和转移瘤是颅内常见的恶性肿瘤,两者的鉴别对于临床治疗决策的制订具有重要意义。本文探讨增强T1WI直方图在胶质母细胞瘤和单发转移瘤鉴别诊断中的应用价值。资料与方法回顾性分析2012年1月-2015年12月于梅州市人民医院行术前MRI检查,并手术或活检病理证实的脑肿瘤患者68例。其中胶质母细胞瘤34例,脑转移瘤34例。术前行常规MRI扫描。采用Image J软件手动于增强T1WI的肿瘤最大层面勾画实质强化部分,分别计算其相应的平均值、最大值、最小值、标准差、峰度值、偏度值。结果脑单发转移瘤实质强化部分的峰度值(1.260±1.271)大于胶质母细胞瘤(0.071±0.667),差异有统计学意义(P<0.05)。以峰度值0.736为临界值,绘制受试者工作特性曲线。曲线下面积为0.792(95%CI:0.676~0.881),鉴别胶质母细胞瘤和单发转移瘤的敏感度为76.47%、特异度为88.24%、阳性预测值为80.65%、阴性预测值为78.38%。结论肿瘤实质强化部分的增强T1WI直方图参数峰度值可用于鉴别胶质母细胞瘤和脑单发转移瘤,为鉴别这2种病变提供可靠的客观依据。

Purpose Glioblastoma and metastasis are the common and aggressive type of brain tumors in adults, and a definitive diagnosis has an important guiding significance to the clinical practice. Our purpose is to investigate the value of post contrast-enhanced T1WI-based histogram analysis in the differential diagnosis of glioblastoma and solitary brain metastasis. Materials and Methods Sixty-eight consecutive patients with glioblastoma or solitary metastasis confirmed pathologically or surgically at Meizhou People＇s Hospital between January 2012 and November 2015 were included in the study. Glioblastoma was diagnosed in 34 patients and solitary brain metastasis was diagnosed in the rest 34 patients. All patients had undergone routine brain MR examination before surgical resection and the imaging data were retrospectively analyzed. The ROIs were manually placed in enhanced solid parts of the tumors on the maximal cross-sectional post contrasted-enhanced T1WI by Image J. Then the mean, standard deviation（SD）, minimum, maximum, skewness and kurtosis were calculated respectively. Results Kurtosis of post contrast-enhanced T1WI of metastasis（1.260±1.271） was statistically higher than that of glioblastoma（0.071±0.667）（P〈0.05）. When the optimal threshold criterion of kurtosis was set at 0.736, the areas under ROC curve of kurtosis was 0.792（95% CI： 0.676-0.881）, and the sensitivity, specificity, positive predictive value and negative predictive value at the optimum cutoff value were 76.47%, 88.24%, 80.65%, 78.38%, respectively. Conclusion Kurtosis of post contrastenhanced T1WI-based histogram is valuable in differential diagnosis of glioblastoma and brain metastasis, and thus provides reliable and objective basis for differentiating the two kinds of tumors.