99Tcm-MIBI甲状腺显像对甲状腺癌诊断价值的再评价

目的 评价99Tcm-甲氧基异丁基异腈(MIBI)甲状腺显像对甲状腺癌的诊断价值.方法 167例甲状腺"冷(凉)"结节患者进行了甲状腺99Tcm-MIBI显像.所有患者均依据病理或穿刺活组织检查诊断.99Tcm-MIBI显像早期相甲状腺结节完全或部分放射性填充视为阳性,轻度或不填充视为阴性;早期相放射性浓聚区与正常组织边界分明者视为分界清楚,否则为模糊;延迟相99Tcm-MIBI从浓聚区清除慢于正常组织者视为清除慢,快于或相同者视为清除快.计算99Tcm-MIBI显像的阳性和阴性预测率,以显像阳性病灶边界模糊和放射性清除慢为标准预测甲状腺癌的发生率.结果 99Tcm-MIBI显像对甲状腺癌的阳性预测率为23.5%(19/81),对甲状腺良性病变的阴性预测率为97.7%(84/86).显像阳性者单独用边界模糊预测甲状腺痛的发生率为36.2%(17/47),单独用清除速度慢预测甲状腺癌的发生率为43.9%(18/41).若放射性浓聚区边界模糊和清除速度慢二者都有时,其预测甲状腺癌的发生率为73.9%(17/23).结论 99Tcm-MIBI甲状腺显像阴性对甲状腺良性结节具有较大的诊断价值;阳性对甲状腺癌的诊断价值不大,但如果同时结合放射性浓聚区边界模糊和清除速度慢,则可提高其诊断价值.

Evaluation of the diagnostic value of 99Tcm-MIBI scintigraphy in thyroid carcinoma

Objective The aim of this study was to evaluate the diagnostic value of 99Tcm-methoxy-isobutylisonitrile(MIBI)scintigraphy in thyroid carcinoma.Methods One hundred and sixty-seven patients with"cold"thyroid nodules visualized on 99TcmO4- imaging underwent 99Tcm-MIBI scintigraphy.The diagnosis was based on excisional histopathology or fine needle aspiration cytology.If the"cold"thyroid nodules showed totally or partially increased 99Tcm-MIBI uptake in the early image,it was defined as positive.Otherwise it was defined as negative.If the border of the positive nodules could be clearly distinguished from the normal thyroid tissue in the early image,it was defined as having the characteristics of a clear boundary.Otherwise it Was defined as a blurry boundary.If the washout rate of the tracer from the positive nodules was slower than the normal thyroid tissue on delayed imaging,the washout rate was defined as slow.Otherwise the washout rate was defined as quick.The positive predictive value(PPV)and negative predictive value(NPV)of 99Tcm-MIBI imaging were calculated.Results The PPV of the positive result in detecting malignant nodules was 23.5%(19/81).The NPV of the negative result in detecting benign nodules Was 97.7%(84/86).The PPV of having a blurry boundary and a slow washout rate as individual character-istics in detecting malignant nodules were 36.2%(17/47)and 43.9%(18/41),respectively.Combining the two characteristics.the PPV for prediction of malignancy was 73.9%(17/23).Conclusions The diagnostic value of negative 99Tcm-MIBI uptake in predicting benign thyroid nodules Was excellent,but a positive 99Tcm-MIBI uptake alone was not so helpful in predicting malignancy in thyroid nodules.However,by combining the two characteristics of a blurry boundary and a slow washout rate the diagnostic value of a positive 99Tcm-MIBI scan could be substantially improved.