动态增强磁共振定量参数联合弥散加权成像对鼻咽癌早期诊断价值的临床分析

The early diagnostic value of DCE-MRI quantitative parameters combined with DWI for nasopharyngeal carcinoma

目的探讨动态增强磁共振(DCE-MRI)定量参数联合弥散加权成像(DWI)对鼻咽癌早期诊断的临床价值。方法105例经鼻咽纤维镜活检确诊的鼻咽肿瘤患者,均接受MRI平扫、DWI扫描与DCE-MRI扫描。根据病理结果,83例鼻咽部良性肿瘤患者纳入良性组,22例鼻咽癌患者纳入恶性组。计算DCE-MRI定量参数,包括容量转移常数(Ktrans)、速率常数(Kep)、血管外细胞外间隙容积比(Ve)。将DWI扫描的0 s/mm2与1000 s/mm2图像处理得到相应ADC值。以鼻咽纤维镜活检结果为金标准,绘制Ktrans、Kep、Ve及ADC值诊断鼻咽癌的ROC曲线,计算ROC曲线下面积、最大约登指数、最佳阈值、灵敏度、特异度、阳性预测值、阴性预测值、准确性。结果良性组Ktrans、Kep、Ve低于恶性组,ADC值高于恶性组(P <0. 05)。DCE-MRI定量参数诊断鼻咽癌的灵敏度、特异度、总符合率分别为77. 3%、84. 3%、82. 9%,DWI诊断鼻咽癌的灵敏度、特异度、总符合率分别为68. 2%、83. 1%、80. 0%,二者联合的灵敏度、特异度、总符合率分别为90. 9%、92. 8%、92. 4%。联合诊断鼻咽癌的总符合率高于DCE-MRI与DWI(P <0. 05)。结论 DCE-MRI定量参数联合DWI可用于鼻咽癌早期诊断,其准确性高于二者单独使用。

Objective To investigate the clinical value of DCE-MRI quantitative parameters combined with DWI in the early diagnosis of nasopharyngeal carcinoma.Methods The clinical data of 105 patients with nasopharyngeal carcinoma who were admitted to our hospital were collected.All cases were confirmed by nasopharyngeal fiberoptic biopsy,and they underwent MRI plain scan,DWI scan and DCE-MRI scan.According to pathological results,the patients were divided into the benign group(n=83)and the malignant group(n=22).Quantitative parameters of DCE-MRI including capacity transfer constant(Ktrans),rate constant(Kep)and extravascular extracellular space volume ratio(Ve)were calculated.The corresponding ADC values were obtained by processing 0 s/m m^2 and 1000 s/m m^2 images of DWI scanning.With the results of nasopharyngeal fiberscopic biopsy as the golden standard,the ROC curves of K trans,Kep,Ye and ADC value were drawn to calculate the area under the ROC curve,the maximum Youden index,the optimal threshold,sensitivity,specificity,positive predictive value,negative predictive value and accuracy for diagnosis of nasopharyngeal carcinoma.Results The Ktrans,Kep and Ve in the benign group were significantly lower but the ADC values were significantly higher than those in the malignant group(P<0.05).The sensitivity,specificity and total coincidence rate of DCE-MRI quantitative parameters in the diagnosis of nasopharyngeal carcinoma were 77.3%,84.3%and 82.9%,respectively while DWI were 68.2%,83.1%and 80.0%,respectively.The sensitivity,specificity and total coincidence rate were 90.9%,92.8%and 92.4%,respectively,when the two indexes were combined.The total coincidence rate of DCE-MRI combined with DWI in the diagnosis of nasopharyngeal carcinoma wassignificantlyy higher than that of DCE-MRI or DWI alone(P<0.05).Conclusion DCE-MRI quantitative parameters combined with DWI can be used for early diagnosis of nasopharyngeal carcinoma,and the accuracy is higher than that of single diagnosis.