3.0 T磁共振扩散加权成像的表观弥散系数有助于鉴别甲状腺良恶性结节

目的评估基于3.0 T MRI的扩散加权成像（DWI）在鉴别甲状腺良恶性结节中的价值。方法回顾性收集2017年10月~ 2018年11月接受手术治疗且获得病理证实的56例甲状腺结节患者，其中男性12例，女性44例，年龄22~79岁（49±15.69岁），包括良性结节50个和恶性结节35个。所有患者使用3.0 T磁共振头颈联合线圈进行常规及DWI扫描；b值选取0、1000 s/mm2获得表观弥散系数（ADC）值。采用独立样本t检验比较甲状腺良恶性结节的差异。使用ROC曲线分析来评估ADC鉴别良恶性甲状腺结节的诊断效能。结果甲状腺良恶性结节的ADC值差异具有统计学意义（P < 0.001），良性甲状腺结节的ADC值高于恶性结节（1.22±0.26）×10-3 mm2/s vs（0.84±0.15）×10-3 mm2/s]；ADC值区分甲状腺良恶性结节ROC曲线下面积0.93，最佳阈值为0.91×10-3 mm2/s，其灵敏度为74.1%，特异性为100%。结论ADC值是鉴别甲状腺良恶性结节的特异性磁共振参数，基于3.0 T MRI的ADC值有助于甲状腺良恶性结节的鉴别诊断。 

Diffusion weighted imaging in the differential diagnosis of benign and malignant thyroid nodules on 3.0 T MRI

ObjectiveTo assess the ability of diffusion-weighted imaging (DWI) on 3.0 T MRI in preoperatively differentiating malignant thyroid nodules from benign nodules.MethodsFrom October 2017 to November 2018, 56 patients with thyroid nodules(50 benign nodules and 35 malignant nodules)were included. All lesions were received surgical resection and confirmed by pathology. There were 12 males and 44 females, with the age from 22 to 79 years old (average 49±15.69). Prior surgery conventional MR and diffusion-weighted imaging (DWI) were examined on 3.0 T MRI scanner with head and neck coils. The b values of 0 and 1000 s/mm2 were used. The independent sample t test was used to compare the apparent diffusion coefficient (ADC) value between benign and malignant thyroid nodules. The receiver operating characteristic (ROC) analysis was performed to assess the diagnostic efficiency.ResultsThe ADC values of benign and malignant thyroid nodules were significantly different (P < 0.001). The ADC value of benign thyroid nodule was (1.22±0.26)×10-3 mm2/s, which was significantly higher than that of malignant thyroid nodules (0.84±0.15)×10-3 mm2/s]. The ADC thresholds of 0.91×10-3 s/mm2 showed the best discriminative value, with the sensitivity of 74.1%, specificity of 100%, and the area under the ROC curve (AUC) of 0.93.ConclusionThe ADC value on 3.0 T MRI was a promising parameter for diagnosing malignant thyroid nodules from benign thyroid nodule.