亚急性甲状腺炎的CT诊断价值

The Diagnostic value of CT in Subacute Thyroiditis

目的探讨亚急性甲状腺炎(SAT)的CT表现,以提高对其认识。方法回顾性分析23例SAT患者的CT影像特征及临床相关资料,所有病例均经手术病理或穿刺活检证实。结果依病变形态分为局限型、弥漫型、混合型。23例中,局限型16例,病变局限发生于单叶或双叶或单叶加峡部,按病变数目又分为单灶型6例和多灶型10例;弥漫型5例,指病变同时浸润左右叶及峡部;混合型即局限与弥漫型并存2例。病灶均表现为边缘模糊不清,呈片状、结节状或不规则阴影,平扫密度低于邻近肌肉,增强后病变呈明显或轻度不均匀强化,病变一般无明显占位效应,其中混合型表现为单叶加峡部弥漫浸润为主,病变向对侧叶过渡,间以对侧叶局限灶散在。23例中发现"过渡征"5例及甲状腺"岛征"4例,7例病变甲状腺包膜不连续,2例合并有颈部淋巴结增大。23例均可触及甲状腺不同程度肿大,12例伴有颈前区压痛,5例实验室检查血FT3、FT4升高的同时131I摄取率下降。结论 SAT的CT表现具有一定特征,患者临床表现、实验室检查亦非常重要,综合考虑有助于提高诊断准确率。

Objective To evaluate the CT features of subacute thyroiditis（SAT）,in order to improve its recognition.Methods The CT findings and clinical data of 23 patients with SAT confirmed by surgery or histopathological examination were analyzed retrospectively.Results The CT findings of 23 patients with SAT were classified into three types according to their morphology as focal（lesion/lesions limited to either one lobe/two lobes or one lobe plus isthmus,16 cases）,diffuse（thyroid were involved wholly including all of two lobes and isthmus,5 cases） and mixed type（coexistence of all features of above mentioned two types,2 cases） and the focal type was subdivided into two categories with regard to number of lesion as single（6 cases） and multiple（10 cases）.All cases manifested ill bordered,irregular,nodular or patchy shadows with the attenuations lower than that of the adjacent muscles on plain CT and mildly or markedly heterogeneous enhanced without significant mass effect,the mixed type was characterized by infiltrative lesion mainly limited to one lobe and transition to opposite lobe via isthmus.Of all 23 cases,the ＂transition sign＂,thyroid capsule discontinuity,the ＂island sign＂ and associated cervical lymph node enlargement were found in five,seven,four and two cases respectively.All cases were found thyroid enlargement in various degree and 12 cases were accompanied by anterior cervical region tenderness in clinical examination.Increased serum FT3,FT4 level and reduced 131 I uptake rate were detected in 5 cases.Conclusion There are some characteristic CT features of SAT,clinical and relative laboratory examination results are also helpful in improving diagnostic accuracy.