磁共振扩散加权成像对原发性肺癌鉴别诊断的价值

Diffusion-Weighted Magnetic Resonance Imaging for a Study of the Value of Differential Diagnosis of Primary Lung Cancer

目的探讨磁共振扩散加权成像（DWI）对原发性肺癌的鉴别诊断价值。方法回顾性分析行常规MRI及DWI扫描（b值取0,800 s/mm2）后经病理及临床随访证实的18例原发性肺癌（恶性组）、12例肺部良性肿块（良性组）患者的影像学资料。以胸髓为参照物采用5分制评分法对肿块与胸髓信号强度比值（LSRs）进行评分,利用感兴趣区法测量各肿块的表观扩散系数（ADC）值,比较原发性肺癌与肺部良性肿块的LSRs、ADC值有无统计学差异,并采用ROC曲线下面积（AUC）比较LSRs、ADC值及两者联合对原发性肺癌的诊断效能。结果原发性肺癌与肺部良性肿块LSRs分别为3.56±1.29、2.42±1.24,ADC值分别为（1.375±0.278）×10（-3）mm2/s、（1.793±0.291）×10（-3）mm2/s,两者的LSRs和ADC值差异均有统计学意义（P〈0.05）。结论LSRs及ADC值均可为原发性肺癌的诊断及鉴别诊断提供有价值的信息,且ADC值的诊断效能优于LSRs,两者联合的诊断效能较ADC值无差异。

Objective To evaluate the feasibility and utility of diffusion-weighted imaging（ DWI） in differential diagnosis value of primary lung cancer. Methods 18 malignant cases and 12 benign cases which were pathology or clinical follow-up proven,were enrolled in the study and underwent routine MRI and DWI scan with a b factor of 0,800 s/mm^2. Lesion-to-spinal cord ratio score（ LSRs） were measured in DWI with a 5-point rank scale method. ADC values of them with ROI were calculated. The quantitative parameters of LSRs,ADC values were statistically analyzed and the diagnostic capabilities of LSRs,ADC values,the combination of both were compared with the area under the ROC curve（ AUC）. Results On DWI,the LSRs of primary lung cancer and benign nodules were 3. 56 ± 1. 29,2. 42 ± 1. 23,and the ADC values were（ 1. 375 ± 0. 278） × 10^（-3） mm^2/s and（ 1. 793 ± 0. 291） × 10^（-3） mm^2/s. Both LSRs and the ADC value of primary lung cancer and benign lesions were significantly different（ P〈0. 05）. By ROC analysis,the AUC of LSRs,ADC values and the combination of both were 0. 743,0. 868,0. 944 respectively. There were statistical differences between LSRs and the combination of both（ Z = 2. 017,P = 0. 043）. Conclusion For quantitative differentiation of primary lung cancer and benign differentiation,ADC value may be more useful and practical than LSR,for primary lung cancer. The diagnosis of the combination of both values and ADC value have no difference.