扩散加权成像对肾上腺肿瘤的鉴别诊断价值

The use of diffusion weighted imaging in the differential diagnosis of adrenal tumor

目的评估3.0T磁共振MRI扩散加权成像(diffusion-weighted imaging,DWI)对肾上腺肿瘤的鉴别诊断价值。方法回顾性分析78例不同病理类型的肾上腺肿瘤患者的DWI图像,所有图像(b值为800sec/mm2)均通过工作站重建获得表观扩散系数(apparent diffusion coefficient,ADC)图,在ADC图中测量肿瘤实性部分ADC值。根据病理结果,将肾上腺肿瘤分为良、恶性两组,通过独立样本t检验对两组之间的ADC值进行统计学分析;对有统计学差异者绘制出ROC曲线并计算曲线下面积,通过灵敏度、特异度及Youden指数确定区分肾上腺良恶性肿瘤的ADC阈值;根据肿瘤的病理类型将良性组分为不同的亚组,通过单因素方差分析对亚组中的ADC值之间的差异进行统计学分析。结果肾上腺良、恶性肿瘤ADC值之间有统计学差异(P<0.05),肾上腺恶性肿瘤的ADC值低于良性肿瘤;ADC阈值为1.09×10-3 mm2/s时,诊断肾上腺良恶性肿瘤的敏感度、特异度分别为94.9%、81.0%,Youden指数为0.759,曲线下面积为0.944;亚组中的肾上腺节细胞瘤与腺瘤、良性嗜铬细胞瘤ADC值之间分别有统计学差异,腺瘤与良性嗜铬细胞瘤ADC值之间有统计学差异。结论 ADC值对肾上腺良恶性肿瘤之间及良性肿瘤的定性诊断具有一定意义,3.0T磁共振扩散加权成像可以应用于肾上腺肿瘤的鉴别诊断。

Objective To evaluate the use of diffusion weighted imaging（DWI）and apparent diffusion coefficient（ADC）at 3.0T MR in the differential diagnosis of adrenal tumors.Methods We retrospectively analysed of DWI images in 78 patients with different pathological types of adrenal tumors.Apparent diffusion coefficient（ADC）（b value=800SEC/mm^2）was obtained through the workstation reconstruction figure in all cases by measuring of solid tumor component.According to the pathological result,benign and malignant adrenal tumors were divided into two groups.The difference between the two groups was statistically analyzed by independent samples t test of ADC values,which was mapped the ROC curve for statistically significance and the area under the curve was calculated.The sensitivity,specific and Youden index were determined in differentiating benign from malignancy in adrenal tumor ADC threshold.The benign group according to the pathological type of tumor was divided into different subgroups.By single factor analysis of the difference between the subgroups,the ADC values were determined for statistical analysis.Results Benign and malignant adrenal tumors was statistically difference between ADC values（P〈0.05）.ADC values were lower in the adrenal benign tumors than malignant tumor with ADC threshold of 1.09×10^-3 mm^2/s.The sensitivity and specifity of the diagnosis of benign and malignancy tumors of the adrenal glands were 94.9%,81.0% respectively.Youden index of 0.759 with the area under the curve was 0.944;Subgroups of benign tumor（the adrenal section cell tumor and adenoma,pheochromocytoma）were statistically difference between ADC values,Adenoma and benign pheochromocytoma was statistically difference between ADC values.Conclusion ADC values of between benign and malignant adrenal tumor has a certain significance.DWI with3.0T magnetic resonance imaging can be widely used in the differential diagnosis of adrenal tumors.