DWI联合动态增强MRI鉴别诊断腮腺肿瘤良恶性

目的 探讨DWI联合动态增强MRI鉴别诊断腮腺肿瘤良恶性的效能。方法 回顾性分析43例（共44个病灶）经病理证实的腮腺肿瘤患者MRI和DWI资料。DWI中测量ADC值，绘制ROC曲线，获得鉴别诊断腮腺多形性腺瘤与恶性肿瘤、腮腺腺淋巴瘤与恶性肿瘤ADC阈值；动态增强MRI中分析时间-信号强度曲线（TIC）类型；计算单独ADC和TIC及二者联合诊断腮腺恶性肿瘤的敏感度、特异度和准确率。结果 多形性腺瘤、腺淋巴瘤、腮腺恶性肿瘤ADC值分别为（1.41±0.06）×10^-3 mm²/s、（0.75±0.05）×10^-3 mm²/s和（1.01±0.05）×10^-3 mm²/s，两两比较差异均有统计学意义（P<0.05）；ROC结果显示鉴别诊断多形性腺瘤与腮腺恶性肿瘤的ADC阈值为1.12×10^-3 mm²/s，鉴别诊断腺淋巴瘤与腮腺恶性肿瘤的ADC阈值为0.70×10^-3 mm²/s；ADC、TIC及二者联合诊断腮腺恶性肿瘤的敏感度分别为61.54%（8/13）、76.92%（10/13）、84.62%（11/13），特异度分别为64.52%（20/31）、83.87%（26/31）、90.32%（28/31），准确率分别为63.63%（28/44）、81.81%（36/44）、88.64%（39/44）。结论 DWI联合动态增强鉴别诊断腮腺肿瘤良恶性效能较高，具有重要临床应用价值。

DWI combined with dynamic contrast-enhanced MRI in diagnosis of benign and malignant parotid gland tumors

Objective To explore the ability of DWI combined with dynamic contrast-enhanced MRI in differetial diagnosis of benign and malignant parotid gland tumors. Methods MRI and DWI data of 43 patients (44 lesions) with pathologically proven parotid gland tumors were retrospectively analyzed. In DWI, ADC was measured and the ROC was drawn to obtain the cut-off value of ADC for differetially diagnosing pleomorphie adenomas and malignant tumors, as well as adenolymphoma and malignant tumors. In dynamic contrast-enhanced MRI, the type of time intense curve (TIC) was assessed. The sensitivity, specificity and accuracy of DWI, dynamic contrast-enhanced MRI and combination of the two methods in diagnosing malignant parotid gland tumors were calculated. Results The ADC value of pleomorphie adenomas, adenolymphoma and malignant tumors was (1.41±0.06)×10^-3 mm²/s, (0.75±0.05)×10^-3 mm²/s and (1.01±0.05)×10^-3 mm²/s, with statistical differences among each group. The cut-off value of ADC was 1.12×10^-3 mm²/s in differentially diagnosing pleomorphie adenomas and malignant tumors, and 0.70×10^-3 mm²/s in differentially diagnosing adenomas and malignant tumors. The sensitivity, specificity and accuracy in diagnosing malignant parotid gland tumors was 61.54% (8/13), 64.52% (20/31) and 63.63% (28/44) for ADC, 76.92% (10/13), 83.87% (26/31) and 81.81% (36/44) for TIC, 84.62% (11/13), 90.32% (28/31) and 88.64% (39/44) for combination of the two methods. Conclusion The ability of combination of DWl and dynamic contrast-enhanced MRI in differentially diagnosing benign and malignant parotid gland tumors is high, which is of great application value.