^18F-FDG PET/CT在纵隔淋巴结鉴别诊断中的价值

Differential diagnosis of mediastinal lymph node by PET/CT

目的探讨18F-FDG PET/CT对纵隔淋巴结的鉴别诊断价值。方法对18F-FDG异常摄取的纵隔淋巴结最终确诊为良性病变者9例(50枚)和恶性病变者13例(35枚)的淋巴结进行比较分析。结果良性组和恶性组淋巴结的大小、CT值、SUV值分别为1.30cm、85.54HU、5.70和2.03cm、37.03HU、7.46,两组之间有统计学差异(P<0.01)。延迟显像前、后良性组和恶性组淋巴结SUV值分别为4.81、4.71和7.61、7.92,均无统计学意义(P>0.05)。良性组4L(22%)、11(20%)、4R(16%)和10R(14%)为好发部位;恶性组2R(17%)、4R(17%)、4L(14%)、7(11%)和10L(11%)部位多见。良、恶性组淋巴结在PET/CT图像上有不同的表现特征。结论淋巴结大小、CT值、SUV值在良?恶性鉴别诊断中有一定参考作用;延迟显像帮助不大;掌握PET/CT影像学特征,结合病史和其他实验室检查等综合分析对纵隔18F-FDG阳性淋巴结的鉴别诊断起重要作用。

Objective To explore the differential diagnosis value of PET/CT in mediastinal lymph node. Methods Patients with positive mediastinal lymph node detected by ^18 F-FDG PET/CT were trailed and observed, and then a contrast analysis was made between 9 benign cases with 50 lymph nodes and 13 cases of mediastinal lymph node metastasis with 35 lymph nodes. Radiotraeer： ^18F-FDG. Imaging instrument： Discovery LS PET/CT. Results The size, CT rumber and SUV of ^18F-FDG positive lymph nodes in the benign and malignant groups were 1.30 cm, 85.54 HU, 5.70 and 2.03 cm, 37.03 HU, 7.46, respectively. The values between these two groups were statistically different （P〈0.01）. The SUV values of benign and malignant groups before and after delayed imaging were 4.81, 4.71 and 7.61, 7.92, which showed no statistical significance （P〉0.05）. According to American Thoracic Society classification, the benign lesions were likely to be in the following body parts： 22% of them in 4L, 20% in 11, 16% in 4R and 14% in 10R, and the malignant lesions usually occurred： 17% of them in 2R, 17% in 4R, 14% in 4L, 11% in 7 and 11% in 10I. Benign and malignant lymph nodes showed different features on PET/CT images. Conclusion The size, CT rumber and SUV of the lymph nodes can be used as refer ences in the differential diagnosis of benign and malignant lesions; delayed imaging shows no reference value;recognition of the features of PET/CT images plays an important role in differential diagnosis of mediastina118 F-FDG positive lymph nodes while the combination with case history and other laboratory examinations should be emphasized.