磁共振扩散成像鉴别炎性及转移性淋巴结的实验研究

目的探讨磁共振扩散成像在动物模型的淋巴结炎与淋巴结转移鉴别中的价值。方法 40只健康新西兰白兔随机分为两组,分别建立淋巴结炎模型（炎症组）和淋巴结转移模型（转移组）。在常规图像基础上测量两组淋巴结的近似表观扩散系数（ADC）。采用接受者操作特性曲线（ROC曲线）评价ADC的诊断价值。结果炎症组及转移组淋巴结ADC值分别为（0.859±0.037）×10^-3mm^2/s和（1.089±0.244）×10^-3mm^2/s（P〈0.05）。ADC值诊断淋巴结良恶性的ROC曲线下面积为0.791,诊断阈值为0.889×10^-3mm^2/s,敏感度80%,特异度75%。结论磁共振扩散成像有助于动物模型良恶性淋巴结的鉴别。

Experimental Study of Diffusion-weighted MRI for Discrimination of Inflammatory and Metastatic Lymph nodes

Objective To evaluate diffusion-weighteghted imaging（DWI） values for discrimination of inflammatory and metastatic lymph nodes in rabbit models.Methods Conventional MRI and DWI images were obtained from 40 rabbits,which were divided into two groups as lymphadenitis model and metastaic lymph node model.Apparent diffusion coefficient（ADC） values of lymph nodes were measured.The diagnostic value of ADC was analyzed by ROC curves.All lymph nodes were confirmed by pathology.Results The average ADC value of inflammatory and metastatic nodes was（0.859 ± 0.037） × 10 ^-3 mm^2 /s and（1.089 ± 0.244） × 10 ^-3 mm^2 /s.There was statistical difference between them（P 〈0.05）.The area under the ROC curves was 0.791.Threshold value to distinguish benign and malignant lesions was 0.889 × 10^ -3 mm^2 /s.Sensitivity,specificity were 80%,75%,respectively.Conclusion DWI is an useful tool for discrimination of inflammatory and metastatic lymph nodes in VX2 rabbits.