甲状腺微小癌的超声征象及其诊断价值

目的 评价灰阶超声在甲状腺微小癌中的诊断价值.方法 回顾性分析58个甲状腺微小癌灶(恶性组)的灰阶超声表现,包括结节的大小、回声水平、内部成分、形态、纵横比、边界、周边声晕、钙化类型,并与61个≤1 cm的甲状腺良性结节(良性组)灰阶超声表现相比较.两组间差别的统计学处理采用X2检验.计算各项超声征象的敏感性、特异性、阳性预测值、阴性预测值和准确性.结果 恶性组中,48.3%为极低回声,98.3%为实性结节,74.1%形态不规整,72.4%纵横比≥1,37.9%有周边不规则声晕,62.1%内含微小钙化.上述超声征象恶性组的显示率明显高于良性组(P＜0.001),而边界不清在两组间的显示率差异无统计学意义.使用极低回声、纵横比≥1、微小钙化三项特异性较高的超声征象作为联合诊断指标,敏感性为86.2%,特异性为77.0%,准确率为81.5%.结论 甲状腺良恶性结节(≤1 cm)的灰阶超声表现有一定差异,综合运用各超声征象对甲状腺微小癌的诊断及鉴别诊断具有较大的临床应用价值.

The characteristics and value of ultrasonography in the diagnosis of thyroid microcarcinoma

Objective To investigate the role of gray-scale sonography in the diagnosis of thyroid microcarcinoma(TMC).Methods The sonographic characteristics of 58 TMC and 61 benign thyroid nodules(≤1 cm)were retrospectively reviewed and compared with each other.The size,echogenicity,internal solid/cystic component,configuration,anteroposterior to transverse dimension ratio(A/T),margin,halo sign and calcification type of the nodules were studied.Statistical analysis was performed using the chi-square test.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of individual sonographic characteristics were calculated respectively.Results In ultrasonography,TMC manifested as marked hypoechoic in 48.3%,solid lesion in 98.3%,irregular-shape in 74.1%,irregular halo sign in 37.0%,with internal microcalcifications in 62.1%.There were significantly statistical differences between the benign and malignant nodules in those findings (P＜0.001).However,there was no obviously statistical difference in the obscure margin.The sensitivity,specificity and accuracy were 86.2%,77.0% and 81.5% respectively when using marked internal hypoechoic echo,A/T≥1 and microcalcification as a new combined criterior.Conclusions The gray-scale sonographic findings between the small benign and malignant thyroid nodules(≤1 cm)are different.Combining these sonographic signs can significantly improve diagnostic value of TMC.