甲状腺结节的MR扩散加权成像与病理对照

目的 探讨甲状腺结节MR DWI表现,评价DWI鉴别甲状腺良、恶性结节的价值.方法 对111例甲状腺单发结节性病变进行MR DWI检查.其中,恶性结节23例,良性结节88例.观察和比较不同良、恶性结节的ADC值差异,确定最佳b值和ADC阈值,并与病理结果相对照.结果 随着b值增大,ADC值均降低.不同b值时甲状腺恶性结节的ADC值均低于良性结节(P均＜().05).甲状腺癌的ADC值明显低于腺瘤和结节性甲状腺肿(P＜0.01),而与甲状腺炎差异无统计学意义(P＞0.05).b=500 s/mm2时,选取ADC值1.70×10-3mm2/s为阈值,诊断甲状腺恶性结节的敏感度、特异度和准确率分别为92.32％、87.51％和86.93％.良、恶性结节的ADC值差异与其病理表现有关.结论 DWIADC值对鉴别甲状腺良、恶性结节有较高价值.

MR diffusion weighted imaging of thyroid nodules: Correlation with pathology

Objective To investigate MR diffusion weighted imaging (DWI) findings of thyroid nodules, and to evaluate DWI in differentiating malignant from benign thyroid nodules. Methods DWI was performed in 111 patients with solitary thyroid nodules (23 with single malignant nodule and 88 with single benign nodule). ADC values were measured and compared. The results were compared with pathology. Results With increase of b value, ADC value reduced. The mean ADC value of malignant nodules was significantly lower than that of benign ones (all P<0.05). The mean ADC value of thyroid cancer was significantly lower than those of adenoma and nodular goiter (both P<0.01), higher than that of thyroiditis, but no statistical significance was found (P>0.05). When b=500 s/mm², taking ADC value of 1.70×10^-3 mm²/s as threshold for diagnosing malignant thyroid nodules, the sensitivity was 92.32%, specificity was 87.51%, and accuracy rate was 86.93%. The differences of ADC values between malignant and benign nodules were significantly relative to pathological findings. Conclusion DWI ADC value is significant for discriminating different thyroid nodules.