动态增强MR定量分析对眼眶良恶性肿块的鉴别诊断价值

Quantitative Analysis of Dynamic Contrast-Enhanced MRI for Differentiating Benign from Malignant Orbital Masses

目的探讨动态增强磁共振成像(DCE-MRI)定量分析对眼眶良恶性肿块的鉴别诊断价值。方法回顾性分析经手术病理或临床随访证实的眼眶肿块64例,其中良性35例、恶性29例。DCE-MRI数据采用改良Tofts双室模型进行处理,获得定量参数:容量转运常数(K^(trans))、返流速率常数(K_(ep))和血管外细胞外间隙容积分数(V_e)。采用独立样本t检验比较良恶性组定量参数的差异,并利用受试者工作特性(ROC)曲线法分析各参数诊断眼眶恶性肿块的效能。结果眼眶恶性组K_(ep)值高于良性组(P=0.015),V_e值低于良性组(P=0.007),两组间K^(trans)值差异无统计学意义(P=0.700)。ROC曲线分析提示以V_e≤0.233诊断眼眶恶性肿块,可以获得最优的诊断效能(AUC 0.741;敏感度65.5%;特异度80.0%)。结论 DCE-MRI定量分析对眼眶良恶性肿块的鉴别诊断有一定价值,可为肿块定性诊断提供依据。

Objective To evaluate the significance of quantitative analysis of dynamic contrast-enhanced（ DCE） MRI in differentiating benign from malignant orbital masses. Methods Sixty-four patients with orbital masses（ 35 benign and29 malignant） confirmed by histopathology or clinical follow-up were retrospectively enrolled in our study. All the DCE-MR imaging data was processed with modified Tofts model. The quantitative parameters including volume transfer constant（ K^（trans））,flux rate constant（ K_（ep））,and extravascular extracellular volume fraction（ V_e） were plotted and calculated. Independent samples T test was used to compare the difference of quantitative parameters between the two groups,and receiver operating characteristic（ ROC） curves were generated to assess the diagnostic accuracy of the parameters. Results The Kepvalues of the malignant masses were significantly higher than those of the benign（ P = 0. 015）,while the V_e values of malignant masses were significantly lower（ P = 0. 007）. No significant difference was found in the K^（trans）values（ P =0. 700）. ROC curves showed that,if setting the V_e≤ 0. 223 as the diagnostic criterion,optimal diagnostic performance could be achieved（ AUC,0. 741; sensitivity,65. 5%; specificity,80. 0%）. Conclusion Quantitative assessments of DCE-MRI are useful in differentiating benign from malignant orbital masses,and may contribute to the qualitative diagnosis.