Objective:To explore the value of multi-parametric MRI for thyroid gland in differentiating benign and malignant thyroid nodules.Methods:From December 2018 to May 2020, 78 patients with 91 post-surgically pathologically confirmed thyroid nodules were enrolled in Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. For each patient, the following MRI findings were obtained including the nodules′ location, size, shape, margin, signal intensity, cystic change, degree and pattern of contrast enhancement, involvement of surrounding structure, and ADC values. The time-intensity curve (TIC) were plotted and subtyped based on dynamic contrast enhancement MRI. The MRI findings between the benign and malignant thyroid nodules were compared using Mann-Whitney U test, χ 2 test or Fisher exact test. Multiple logistic regression analysis was used to select independent predictive variables and build a combined model, and the ROC curve was used to evaluate the diagnostic performance of each MRI finding and the combined model. Results:Between the benign and malignant thyroid nodules, the significant differences were found in size, shape, margin, presence of cystic changes, T 1WI signal intensity, ADC value, enhancement homogeneity, TIC subtypes and presence of thyroid capsule involvement ( P<0.05). Multivariate logistic analysis showed that ill-defined margin (OR=77.61), no presence of cystic changes (OR=36.11) and difference between TIC subtypes (OR=83.41) were independent predictive variables, and the area under the ROC curve (AUC) was 0.879, 0.788, and 0.751, respectively. The AUC, sensitivity and specificity of the combined model were 0.977, 0.986, and 0.904, respectively. Conclusions:Thyroid multi-parametric MRI derived findings can be used for the differential diagnosis of benign and malignant nodules. Combined with the independent risk factors with ill-defined margin, no presence of cystic changes, TIC of type plateau or washout, the diagnostic model has a higher diagnostic efficiency.

目的 探讨采用甲状腺专用表面线圈的术前多参数MRI特征对甲状腺癌区域淋巴结转移的预测价值.材料与方法 回顾性分析中国医学科学院肿瘤医院深圳医院经手术病理证实的甲状腺癌51例,均行甲状腺病灶切除及颈部淋巴结清扫,术前均行3.0 T增强MRI扫描.以术后病理为对照,分析比较转移淋巴结和非转移淋巴结的MRI征象,构建转移淋巴结的预测模型.计量资料的比较采用t检验或U检验,计数资料比较采用χ2检验,多元逻辑回归分析用于构建预测模型,ROC曲线用于评估预测模型的诊断效能.结果 51例甲状腺癌患者共135枚淋巴结纳入研究,其中转移淋巴结74枚,非转移淋巴结61枚.转移与非转移淋巴结的长短径、ADC值、T1WI和抑脂T2WI信号、形状、边缘、是否囊变、强化程度等差异具有统计学意义(P均<0.05).其中抑脂T2WI呈混杂信号、明显强化、低ADC值(<0.91×10-3 mm2/s)是转移淋巴结的独立预测因子,联合这3个MRI征象所建立的预测模型其AUC为0.93,敏感度为82.4％,特异度为88.5％.甲状腺癌伴有桥本氏甲状腺炎时,其Ⅵ区非转移淋巴结的长径、短径均大于不伴桥本氏甲状腺炎组(P<0.05).结论 术前多参数MRI特征对甲状腺癌区域淋巴结转移有较高的预测价值,转移淋巴结多表现为抑脂T2WI呈混杂信号、明显强化、更低的ADC值,为甲状腺癌的术前临床决策提供非常有价值的依据.