肺部病变99mTc-甲氧异丁基异腈断层显像检查

目的 探讨^99mTc-甲氧异丁基异腈（^99mTc-MIBI）显像对肺癌探测的灵敏度，特异性。方法 嘱患者早餐吃油煎鸡蛋喝牛奶，静脉注入1.11GBq^99mTc-MIBI,分别在1h和2h进行胸部双探头断层显像检查,20s/帧,共64帧,滤波反投影重建图像,根据视觉判断确定病灶显像为阳性或阴笥,在计算机上用ROI技术划出阳性病灶和对侧肺对照区,测定计数求出靶本(T/N)比例.结果 肺部良恶性病灶早期和延迟显像的阳性率分别为66.2%(43/65)和69.8%(37/53),早期显像诊断肺癌的灵敏度和特异性分别为73.9%(34/46)和52.6%(10/19).延迟显像的灵敏度是76.3%(29/38),部分显像阴性的肺癌病灶直径较大,46例肺癌和19例肺部良性病变在早期和延迟显像的靶本比值和阳性率之间差异无显著性;鳞癌,腺癌和良性病变的靶本比值比较差异无显著性.结论 ^99mTc-MIBI作为肿瘤阳性显像剂,其阳性结果应同时参考放射学,临床治疗和随访结果.否则,^99mTc-MIBI阳性显像不易鉴别良恶性病变.

99mTc- MIBI SPECT in 65 cases of pulmonary malignant and benign lesions

Objective To investigate the sensitivity and specificity of 99mTc-MIBI imaging in lung cancer. Methods Patients with pulmonary lesion were given fried egg and milk and then imaged 1 h and 2 h after injection of 1.11GBq MIBI using a dual head SPECT. Then, the tumor to normal (T/N) lung counts ratio was calculated with ROI technique.Results The positive rates of the early and delayed 99mTc-MIBI images were 66.2%(43/65)and 69.8%(37/53), respectively. The sensitivity and specificity of lung cancer in the early images were 73.9%(34/46)and 52.6%(10/19)respectively, and the sensitivity in the delayed images was 76.3%(29/38). In some patients with negative findings, the diameter of the cancerous lesion was relativly longer. The T/N ratios and the positive rates in the early and delayed images showed no statistical difference between the 46 lung cancers and 19 benign pulmonary lesions. Also the differences in T/N ratios among the squamous cell carcinoma,adenocarcinoma and benign lesions were not remarkable.Conclusion In distinguishing malignant from benign pulmonary lesions, one must take in account of the radiological, clinical findings and results in addition to the positive 99mTc-MIBI imaging.