甲状腺过锝酸盐显像和半定量分析对亚急性甲状腺炎误诊甲亢的鉴别

Identification of subacute thyroiditis misdiagnosed as hyperthyroidism by semiquantitative analysis of thyroid imaging TcO_4^-

目的回顾分析127例甲亢患者中,甲状腺显像和半定量分析对亚急性甲状腺炎(简称亚甲炎)误诊甲亢的鉴别价值。方法①回顾病例:127例临床诊断为甲亢的患者,进行了放射性核素甲状腺静态显像。其中男33例,女94例,年龄21～66岁,平均(35.23±11.76)岁;②显像方法:过锝酸盐(Sodium Pertechnetate 99mTc Injection,99mTcO4-)平面静态显像,剂量4.5mCi,给药后15min显像,采集时间5min;③从显像结果并结合其他检查,分别统计符合甲亢和亚甲炎诊断的例数,以及亚甲炎误诊率;④通过计算机感兴趣区(return on injection,ROI)半定量技术,分别计算甲亢和亚甲炎患者影像的甲状腺与颈部软组织放射性计数比值、与同侧颌下腺比值、与同侧腮腺比值,并通过t检验统计分析两者间的差异性。结果①127例甲亢患者影像中,符合甲亢表现的为92.91%(118/127),符合亚甲炎表现的(即误诊率)为7.09%(9/127),符合率100%;②甲状腺与颈部软组织ROI放射性计数比值,甲亢和亚甲炎分别为46.12±19.83和2.90±1.32,两者有统计学差异(t=8.77,P<0.01);与同侧颌下腺比值分别为20.74±12.87和0.94±0.37(t=6.79,P<0.01);与同侧腮腺比值分别为18.94±10.61和1.05±0.54(t=7.04,P<0.01)。结论部分亚甲炎(7.09%)在临床上可被误诊甲亢,甲状腺显像及放射性计数半定量比值是一种简便而价值优良的鉴别手段。

Objective To retrospectively explore the value of the thyroid imaging and semiquantitative analysis in differentiating the subacute thyroiditis misdiagnosed as hyperthyroidism among 127 cases of hyperthyroidism. Methods ① Review of cases comprised 127 patients diagnosed as hyperthyroidism in clinic, who underwent static imaging of radionuclide thyroid, including 33 males, 94 females, aged 21 to 66 years, with an average of 35.23±11.76 years old; ② Imaging method inclued Sodium Pertechnetate 99mTc Injection （99mTcO4 ） plane static imaging. Dose was 4.5 mCi. The imaging was displayed 15 min after administration and the time for acquiring imaging was 5 min; ③ The case in line with the diag nosis of hyperthyroidism and subacute thyroiditis number and of the rate of misdiagnosis were calculate from the imaging results combined with other inspection; ④ The ratio of radioactivity in the thyroid and neck soft tissue, the ipsilateral sub mandibular gland, and the ipsilateral parotid gland in patients with hyperthyroidism and subacute thyroiditis were respec tively calculated on Return On Injection （ROD via Semi quantitative technique. Statistical analysis was conducted using t test to explore the differences between of them. Results ① By analysing the images of 127 cases with hyperthyroidism, the rate in line with the performance of hyperthyroidism was 92.91% （118/127） and the rate in line with the performance of subacute thyroiditis （misdiagnosed） was 7.09± （9/127）. Coincidence was 100%; ② The ratio of radioactive counts from ROI in thyroid and neck soft tissue in patients with hyperthyroidism and suhacute thyroiditis were 46.12± 19.83 and 2.90±1.32, respectively. There were significant differences between of them （ t = 8.77, P 〈0.01）. The ratios of the ip silateral submandibular gland were 20.74t 12.87 and 0.94..0.37 （ t =6.79, P 〈0.01）. And the ratios of ipsilateral pa rotid gland were 18.94..10.61 and 1.05--0.54 （ t 7.04, P〈0.01）. Conclusion Certain patients with subacute thyroiditis can be misdiagnosed as hyperthyroidism in clinic. Thyroid imaging and semi quantitative analysis is a simple and excellent means for the identification of these two disorders.