各种CT征象联合应用在甲状腺微小乳头状癌诊断中的价值

Value of CT features in diagnosing papillary thyroid microcarcinoma

目的：探讨各种CT征象联合应用在甲状腺微小乳头状癌（PTMC）诊断中的价值。方法回顾经病理证实的直径0．5～1．0 cm的PTMC的CT资料，共189例206个，分析结节形态、咬饼征、微钙化及增强后模糊等征象，并与同期直径0．5～1．0 cm的156例218个微小结节性甲状腺肿（TMNG）的CT征象相比较，计算各种CT征象及其联合应用的敏感度、特异度、准确度。结果16个PTMC及9个TMNG因桥本甲状腺炎或锁骨伪影而排除，余190个PTMC及209个TMNG中，结节在形态、咬饼征、微钙化及增强后模糊方面均有统计学差异（P＜0．05）。单一CT征象中，形态不规则的敏感度最高（92．0％），微钙化的特异度最高（94％），咬饼征的准确度最高（85％）；两个CT征象联合中，咬饼征加微钙化的特异度最高（100％），形态不规则＋增强后模糊的敏感度和准确度均最高（分别81％和87％）；3个CT征象联合中，形态不规则、咬饼征、微钙化和咬饼征、增强后模糊、微钙化特异度最高（均100％），形态不规则、咬饼征、增强后模糊的敏感度及准确度最高（分别63％和81％）；4个CT征象联合中，诊断的敏感度、特异度、准确度分别为9％、100％、57％。结论尽管不同CT征象的单独应用在PTMC诊断中具有较高敏感度，但特异度较低，不同CT征象的联合可明显提高PTMC诊断的特异度。

Objective To investigate the value of CT features in diagnosing papillary thyroid microcarcinoma （PTMC）. Methods CT features of 206 lesions in 189 patients with histologically confirmed PTMC were retrospectively analyzed. The morphology , cookie bite sign,.microcalcifications and enhancement were compared with 218 lesions in 156 cases of micronodular goiters . （MNG）. Results 16 lesions of PTMC and 9 lesions of MNG were excluded because of Hashimoto thyroiditis or image artifact from the clavicle..190 lesions of PTMC and 209 lesions MNG were included in this study..The diameter of lesions was 0.5-1.0 cm..The morphology,.cookie bite sign,.microcalcifications and enhancement of the lesions were all significantly different between PTMC and MNG（P〈0.05）. The irregular shape was most sensitive （92%）, microcalcifications most specific （94%）, and the cookie bite sign most accurate （85%）. The combination of cookie bite sign and microcalcifications increased the sensitivity to 100%. irregular shape and contrast enhancement resulted in sensitivity of 81% and accuracy of 87%..Combining three signs together,.irregular shape, microcalcifications, cookie bite sign or enhancement showed the highest specificity （100%） whereas irregular shape, cookie bite sign and microcalcifications showed the highest sensitivity （63%） and accuracy （81%）. Combining all four signs together resulted in sensitivity,.specificity,.and accuracy of 9%,.100% and 57% respectively..Conclusion Single CT feature showed a high sensitivity and low specificity in diagnosing PTMC. Combination of different CT signs significantly improved the specificity.