甲状腺结节样病变超声诊断的最大似然判别法分析

Utrosonic diagnosis of thyroid nodular lesions by maximum likelihood discriminant analysis

目的探讨甲状腺癌与甲状腺良性结节(甲状腺腺瘤和甲状腺结节性增生)的超声鉴别方法以提高甲状腺结节样病变的诊断水平。方法回顾性分析经病理确诊的甲状腺癌83例、甲状腺良性结节295例。经过χ2检验确定有显著性差异的超声观察指标进行最大似然判别法分析。应用独立事件的概率乘法定理得到判别对象归属某类的概率(Pk),判别对象归属所求得的概率大的那一类病变。结果甲状腺病灶边界、边缘、声晕、包膜、回声性质、内部回声情况、病灶内成簇细钙化、散在细钙化、病灶相邻处包膜、病灶内血流频谱舒张期反向血流或三相波、颈部转移性淋巴结、径线纵横比、周边血流信号13项超声观察指标在甲状腺癌组与甲状腺良性结节组间差异有统计学意义。最大似然判别法分析对二者诊断的准确率分别为甲状腺癌组90.52%,甲状腺良性结节组93.74%。结论甲状腺病灶包膜、内部回声情况、病灶内成簇细钙化、病灶相邻处甲状腺包膜、病灶内血流频谱舒张期反向血流或三相波、颈部转移性淋巴结等超声特征对甲状腺癌与甲状腺良性结节的鉴别诊断起重要作用,最大似然判别法在甲状腺结节样病变超声诊断中有重要意义。

Objective To study an uhrosound identification method between thyroid carcinoma and benign thyroid nodule（thyroid nodular hyperplasia and adenoma） and improve the diagnosis of thyroid nodules. Methods The ultrosonic signs in 83 cases of thyroid carcinoma and 295 cases of benign thyroid nodule were analyzed retrospectively. All cases were histologically confirmed. Maximum like- lihood discriminant analysis was employed to discriminate a series of observation indexes,which had a statistically significant difference determined by Chi-square test. Multiplication theorem of probability of independent events was obtained to determine probability of cer- tain types of object ownership. Identifying object come under jurisdiction of the type probability of large. Results 13 indexes were found to be significant and evident for making a distinction between thyroid carcinoma and benign thyroid nodule, such as lesion border, edge, surrounding acoustic halo, envelope, echo property, internal echo of lesion, cluster fine calcifications within lesion, thyroid capsule adjacent lesion, blood stream spectrum of reversed diastolic flow or three-phase wave within lession, cervical metastatic lymph node, as- pect ratio, perilesion blood flow. The accuracy rates of discrimination analysis for thyroid carcinoma and benign thyroid nodule were sep- arately 90.52% and 93.74%. Conclusion The importance of indexes including lesion envelope, internal echo of lesion, cluster fine calcifications within lesion , thyroid capsule adjacent lesion, blood stream spectrum of reversed diastolic flow or three-phase wave within lession, and cervical metastatic lymph node should be highlighted in the differentiation of thyroid carcinoma and benign thyroid nodule. Maximum likelihood discriminant method has important significance in uhrosonic diagnosis of thyroid nodular lessions.