PET与CT在肺癌诊断中的联合应用

目的:遴选CT鉴别肺部病变良恶性的征象,利用这些征象降低PET在肺癌诊断中的假阳性和假阴性。方法:42例肺部病变患者行PET和CT检查。若肺部病变放射性摄取明显增高,同时SUV≥2.5,判断为恶性病变。若肺部病变有轻度放射性摄取,但其摄取程度低于或明显低于纵隔,SUV2.5,判断为良性病变。选择CT图像上10种最常见的恶性病变征象和10种常见的良性病变征象加以对照分析。结果:PET显像高代谢恶性病变(真阳性)组11例,在CT上都观察到较多的符合征象;PET显像低代谢良性病变(真阴性)组11例,其中有10例在CT上都观察到较多符合征象,只有1例病变观察到得符合征象和质疑征象基本相等。而PET显像高代谢良性病变(假阳性)组10例,其中有9例在CT上观察到较多质疑征象,另有1例观察到较多符合征象;PET显像低代谢恶性病变(假阴性)组10例,在CT上都观察到较多质疑征象。结论:CT征像可以帮助降低PET在肺癌诊断中的假阳性和假阴性。

The combined application of CT and PET in diagnosing lung cancer

Objective：Selecting special signs of lung disease in CT image and identify the malignant features or benign features.And using these features to decrease the false positive and false negative in PET for differentiate malignant and benign lung lesions.Methods：Forty-two patients with lung disease examined with CT and 18 F-FDG PET imaging.We used a cutoff of 2.5 of SUV to divide lesion into benign or malignant（hypo-metabolizing or hyper-metabolizing）.Using 10 malignant and 10 benign features of CT images to observe the quality of the disease.Results：In true positive group,the 11 patients of malignant tumors with a higher uptake in PET imaging,all of their lesions had more coincident features than features in CT images.Similarly,in true negative group,11 patients of benign tumors with a lower uptake in PET imaging,the lesions of 10 patients had more coincident features than sceptical features in CT images,except for both coincident features and sceptical features were observed equal approximately in one patient.While in false positive group,10 patients of benign tumors with a higher uptake in PET imaging,the lesions of 9 patients had more sceptical features than coincident features in CT images except one patient had more coincident features.Similarly,in false negative group,the 10 patients of malignant tumors with a lower uptake in PET imaging,all of their lesions had more sceptical features than coincident features in CT images.Conclusion：We can combined with the information of configuration and features of the lesions in CT images to decrease the false positive and false negative diagnosis in PET for differentiating malignant tumors from benign lung lesions.