肿瘤阳性显像剂肺内非特异性摄取的SPECT/CT显像特点与成因分析(附11例报告)

Characteristics and causes of non-specific uptake of SPECT/CT imaging in 11 cases of lung cancer positive imaging agents

目的探讨肿瘤阳性显像剂肺内非特异性摄取SPECT/CT显像特点、鉴别方法以及形成的原因。方法回顾性分析2014年9月至2016年3月在北京协和医院核医学科行^(99m)Tc-甲氧基异丁基异腈(methoxy isobutyl isonitrile,MIBI)和^(99m)Tc-HYNIC-TOC SPECT显像(含胸部显像),胸部可见异常放射性浓聚但同机或异机融合CT均未提示占位性病变的患者。观察胸部异常浓聚灶的特点,勾画摄取部位感兴趣区,并在对侧同水平复制勾画感兴趣区,计算平均摄取值及靶/本底比值。收集患者的临床资料,包括病史、其他影像学及实验室检查结果。结果 5668例行^(99m)Tc-MIBI和^(99m)Tc-HYNIC-TOC SPECT显像(含胸部显像)的患者中,出现胸部异常放射性浓聚灶并行同机或异机融合CT均未提示占位性病变者共11例,其中使用^(99m)Tc-MIBI显像5例,^(99m)TcHYNIC-TOC显像6例。11例异常浓聚灶形态均为圆形,右肺5例,左肺6例。靶/本底比值分别为2.66、4.01、6.96、8.19、10.50、11.16、11.16、14.89、15.16、28.13和32.64。11例患者的病史、药物使用史及实验室检查均无交叉(临床资料不相同)。结论肺内非特异性摄取易发生在使用^(99m)Tc-MIBI和^(99m)Tc-HYNIC-TOC示踪剂进行显像的核医学检查中,可能与这两种示踪剂形成微小栓子栓塞肺内血管有关;平面显像与肺部肿瘤性病变鉴别困难,SPECT/CT融合显像联合有助于除外这种肺内的非特异性摄取。

Objective To retrospectively analyze the characteristics of SPECT/CT imaging of non-specifi c uptake of tumor-positive imaging agents in the lung and the possible causes of formation.Method A retrospective analysis was made of the patients who underwent 99mTc- MIBI and 99mTc-HYNIC-TOC SPECT imaging in Nuclear Medicine Department of our hospital from 2014 to 2016. Abnormal radioactivity concentration was observed in the chest, but no space-occupying lesions were detected by CT in the same machine or in different machine fusion. For the characteristics of abnormal chest foci, circular and thoracic regions of interest were delineated and the regions of interest were duplicated at the same level on the opposite side. Mean uptake values and target/background ratios were calculated. Clinical data including medical history, other imaging and laboratory fi ndings were collected. Result From 2014 to 2016, 99mTc-MIBI and 99mTc-HYNICTOC SPECT were used as tracers in patients with chest imaging in our hospital. There were 11 patients with abnormal chest radioactivity concentration without space-occupying lesions revealed by CT in the same machine or in the other machine, including 5 patients with 99mTc-MIBI imaging and 6 patients with 99mTc-HYNIC-TOC imaging. The abnormal foci were round in 11 cases, 5 in the right lung and 6 in the left lung. The target/background ratios were 2.66, 4.01, 6.96, 8.19, 10.50, 11.16, 11.16, 14.89, 15.16, 28.13 and 32.64, respectively. The medical history, drug use history and laboratory examination of 11 patients were not cross-sectional. Conclusion Non-specifi c uptake of lung is easy to occur in nuclear medical examination using 99mTc-MIBI and 99mTc-HYNIC-TOC tracers. It may be related to the formation of colloidal embolism of pulmonary vessels by these two tracers. It is diffi cult to differentiate between planar imaging and pulmonary neoplasms. SPECT/CT fusion imaging can help to exclude this non-specifi c uptake in the lung.