甲状腺癌的CT诊断

目的分析甲状腺癌及其颈部转移淋巴结的ＣＴ表现，探讨肿瘤侵犯周围重要器官的诊断指征。方法回顾性分析经手术及病理证实的５２例甲状腺癌的术前ＣＴ表现。结果５２例原发肿瘤均密度不均，３２例边缘不规则（８２．５％），１１例原发肿物及５例转移淋巴结内有细颗粒状钙化，４例原发肿瘤及６例转移淋巴结内有囊性变伴囊壁高密度乳头状结节，手术证实气管受侵２２例；１０例ＣＴ示气管内壁呈锯齿状，５例肿物突入气管腔内而明确诊断。食管受侵２１例，颈动脉受侵１０例。以肿物包绕食管１／２周或颈动脉１／３周以上为侵犯的诊断指标，敏感性分别为７１．４％、１００．０％；特异性分别为９６．３％、９５．２％。结论原发肿物及转移淋巴结内颗粒状钙化及囊性变伴高密度乳头状结节是甲状腺癌（特别是乳头状癌）的特征性密度变化。ＣＴ增强扫描对诊断甲状腺癌及评价其与周围结构的关系和制定手术方案十分重要

CT diagnosis of thyroid carcinoma

Purpose To study the CT appearances of thyroid carcinoma and its cervical metastatic lymphadenopathy, as well as to evaluate the diagnostic criteria of tumor invasion of adjacent structures. Methods CT findings of surgery and pathology proved thyroid carcinoma in 52 patients were analyzed. Results All of the primary tumor were heterogeneous in density, 32 tumors (82.5%) were ill defined. Fine granular calcifications were revealed in 11 primary tumors and metastatic lymph nodes in 5 cases. Cystic formation with intracystic high density papillary like nodules were found in 4 primary tumors and metastatic lymphadenopathy in 5 cases. Trachea, esophagus and carotic artery invasion were proved by surgery in 22, 21 and 10 cases respectively. Serrated inner wall and tumor nodule protrusion into tracheal lumen were the definite signs of trachea invasion. Use tumor encasement over 1/2 of the circumference of esophagus and 1/3 of the circumference of carotid artery as the diagnostic criterion of invasion, sensitivity was 71.4%, 100.0%; specificity was 96.3%, 95.2% respectively. Conclusion Fine granular calcification and cystic formation with high attenuaion intracystic papillary like nodules were characteristic manifestations of primary thyroid carcinoma (especially papillary carcinoma) and its metastatic lymphadenopathy as well. Contrast enhanced CT scan is helpful in the diagnosis of thyroid carcinoma and the delineation of tumor extent, which is very important in surgical planning.