PET/CT在诊断局灶性机化性肺炎中的作用

The Application of PET/CT in Diagnosing Focal Organized Pneumonia

目的探讨PET/CT诊断局灶性机化性肺炎的价值。方法 15例疑肺部新生物患者行18F-FDG PET/CT检查,并经手术和病理诊断为机化性肺炎。分析其临床表现以及病灶的CT征象,测量病灶FDG最大摄取值,并与同期66例周围型肺癌比较。结果局灶性机化性肺炎主要症状为咯血(8例),咳嗽(4例)和发热(3例)。所有病例均为单发病灶,病灶呈结节状软组织密度影13例,大片实变1例,絮状1例。与周围型肺癌相比,病灶多呈多边形或不规则形(χ2=27.305,P=0.000),贴近胸膜或位于胸膜下(χ2=34.046,P=0.000),边缘模糊或毛糙或外围渗出(χ2=39.777,P=0.000),少分叶(χ2=16.848,P=0.000),而胸膜牵拉和毛刺两者无明显区别(分别为χ2=0.007,P=0.932和χ2=0.902,P=0.342)。其FDG摄取值(SUVmax为3.7±1.7)与肺癌(SUVmax为10.4±5.4)有显著差异(t=8.298,P=0.000)。2例PET/CT征象类似周围型肺癌。结论局灶性机化性肺炎临床表现不具有特异性,其PET/CT征象具有一定特征,少数病灶难以与周围型肺癌鉴别。

Objective To discuss the clinical value of PET/CT scanning in diagnosing focal organized pneumonia（FOP）.Methods During the period from March2006 to October 2012,a total of 15 patients with suspected lung tumors（study group） were admitted to authors＇ hospital.18 F PET/CT scanning was carried out in all patients,and surgical results and pathological examination proved that the diagnosis was organized pneumonia in all patients.Other 66 patients with peripheral lung cancer encountered during the same period were collected and used as the control group.The clinical manifestations and CT findings were analyzed,the maximal standard uptake values（SUVmax） of lesions were measured,and the results were compared with that of the control group.Results The main symptoms of FOP included hemoptysis（n =8）,cough（n=4） and fever（n=3）.The lesion was unifocal in all patients.On CT scans the lesions presented as nodular soft tissues density in 13 cases,larger sheet-like consolidation shadow in one case and fluffy appearance shadow in one case.Compared with peripheral lung cancer,most of FOP lesions were characterized by polygons or irregular appearance（χ^2= 27.305,P=0.000）,and were located close to the pleura or beneath the pleura（χ^2= 34.046,P=0.000）.The lesions had blurred or coarse edge,or peripheral exudates（χ^2= 39.777,P=0.000）,and few lesions had lobulated border（χ^2= 16.848,P=0.000）.No obvious differences in the occurrence of pleura tail sign and speculation sign existed between the study group and the control group（χ^2= 0.007,P=0.932,and χ^2= 0.902,P=0.342 respectively）.Statistically significant difference in SUVmax existed between the two groups（3.7 ± 1.7 vs.10.4 ± 5.4,t=8.298,P=0.000）.In two patients of FOP,the lesions had similar PET /CT manifestations as peripheral lung cancer.Conclusion Clinically,focal organized pneumonia has no characteristic manifestations,nevertheless,it carries certain PET /CT features although it is still very difficult to differentiate it from peripheral lung cancer in a few patients.