DWI在肺癌淋巴结定性诊断中的临床研究

Application of DWI in Differential Diagnosis of Lymph Nodes in Patients with Lung Cancer

目的:探讨磁共振扩散加权成像在肺癌纵隔及肺门转移性淋巴结诊断中的应用价值。方法:25例肺癌患者,在术前行肺部MRI常规和DWI扫描(b=0 s/mm2,800s/mm2),获取ADC图,并测量纵隔和(或)肺门淋巴结的ADC值。根据术后病理,将由ADC图检出的78枚淋巴结分为两组:非转移性淋巴结43枚,转移性淋巴结35枚。用t检验比较转移性与非转移性淋巴结的ADC值之间差异是否有统计学意义;通过ROC曲线分析ADC值鉴别转移性与非转移性淋巴结的诊断价值。结果:转移性淋巴结的ADC值明显小于非转移性淋巴结(t0-800=5.888,P<0.05)。取ADC=2.210×10-3mm2/s作为转移性与非转移性淋巴结的鉴别诊断阈值,其敏感性、特异性、阳性预测值、阴性预测值分别为82.9%、69.8%、69.0%、83.3%。结论:扩散加权成像对肺癌患者的纵隔和(或)肺门淋巴结转移有一定的鉴别诊断价值。

Purpose： To explore the value of diffusion-weighted imaging（DWI） in differentiating metastatic from non-metastatic mediastina and hilar lymph nodes in patients with lung cancer. Methods： Twenty-five patients with lung cancer before surgical operation were examined with conventional MR and DW imaging （b=0s/mm2, 800 s/mm2）. ADC map was obtained automatically. Apparent diffusion coefficient （ADC） of each mediastinal and （or） hilar lymph nodes were measured on ADC maps. According to the operative and pathological findings, 78 lymph nodes were divided into two groups： 43 non-metastatic lymph nodes, 35 metastatic lymph nodes. Student＇ s t test was used to compare the difference between metastatic and non- metastatic lymph nodes, and ROC curve was used to analyze the diagnostic performance of ADC value in differentiating metastatic from non-metastatic lymph nodes. Results： The ADC value of metastatic lymph nodes was obviously lower than that of non-metastatic lymph nodes （t0-800=5.888, P〈0.05）. The threshold of ADC value in differentiating metastatic from non-metastatic lymph nodes was 2.210 × 10^-3mm2/s, and the sensitivity, specificity, positive predictive value and negative predictive value was 82.9%, 69.8%, 69.0% and 83.3%, respectively. Conclusion： DWI has diagnostic value in differentiating metastatic from non- metastatic mediastina and （or） hilar lymph nodes in patients with lung cancer.