A Comparison Of Radiological And Clinical Features Of Focal Organizing Pneumonia And Lung Cancer

Purpose:Investigate the imaging features.of organizing pneumonia(OP)and lung cancer,and to improve the value of CT in the differential diagnosis between Organizing Pneumonia and lung cancer.Materials and Methods:This is a retrospective study in which 8 patients with pathologically confirmed Organizing Pneumonia were enrolled,with 31 cases of randomly selected lung cancer as control group.The differences of clinical features,CT findings and enhancement pattern of lesions between two groups were compared.The ethics committee of Yanbian university hospital located in Yanji,China approved the study.This was a retrospective study of the patients involving existing clinical data;therefore,no change in treatment and/or follow-up of the patients was done,so no written informed consent was required.The main clinical manifestations were cough,sputum,hemoptysis,chest pain,shortness of breath,fever etc.we concentrated mainly on comparative analysis of the CT performances.The results were analyzed with Independent-Samples T test,and we also use the Pearson?2 test for the comparison between the two groups.A P value of<0.05 was considered statistically significant.The following were used as interpretation of CT image;Location,Distribution,Size,Bronchi,Corona radiata sign(Spiculation Sign),Cavity,Necrosis,CT enhancement,Calcification,Ground-glass opacity,Peribronchovascular opacities,Bronchiectasis,Nodules and Lymph node.Result:There were 31 cases of lung cancer in total,including 18 male cases and 13 female cases.The ages ranged from 41 to 82 years old,with mean age of 63.42±10.69 years old.The lesions occurred at left lobe in 10 cases(32.3%),including left upper lobe in 5 cases,left lower lobe in 3 patients,left hilum 2 patients.And the lesions occurred at right lobe in 21 cases(67.7%),including right upper lobe in 10 cases,in right middle lobe 3 cases,in right lower lobe 5 cases and in right hilum 3 cases.The number of cases that occurred at right lobe was obviously more than that of left lobe(21:10).The lesions were mainly distributed in central region 21cases(67.7%)while 10 cases(32.3%)were located in peripheral region.The size of lesion ranged froml.7?11cm,with mean size of 4.98±2.12 cm.The CT changes for the lesions are spiculation sign in 11 cases(35.5%),normal bronchus in 7 cases(22.6%),abnormal bronchus in 24 cases(77.4%)which included 1 dilated,10 narrowed and 13 blocked bronchus,cavity in 8 cases(25.8%),necrosis in 4 cases(12.9%),average arterial phase enhancement of the lesion 28.4HU,average vein phase enhancement of the lesion is 25.1HU and the CT changes at the surrounding areas are ground glass opacity is seen in 16 cases(51.6%),consolidation in 28 cases(90.3%),peribronchovascular opacity in 18 cases(58.1%),bronchiectasis in 3 cases(9.7%),nodule in 17 cases(54.8%),lymph node enlargement in 24 cases(77.4%).In the Organizing Pneumonia group,there were 7 male cases and 1 female case.The ages ranged from 35 to 75 years old,with mean age of 51.38±12.83 years old The lesions occurred at left lobe in 2 cases(25%),both in left lower lobe.And the lesions occurred at right lobe in 6 cases(75%),including right upper lobe in 2 patients,right middle lobe 2 cases,and in right lower lobe 2 patients.In this group,the number of cases that occurred at right lobe was also higher than that of left lobe(6:2).But the difference had no statistical significance(P>0.05).The lesions were only present in peripheral region 8 cases(100%).The size of lesion ranged from 1.3?-6cm,with mean size of 3.33± 1.64cm.The CT changes for the lesions are spiculation sign in 0 cases,normal bronchus is seen in 6 cases(75%),abnormal bronchus in 2 cases(25%)which include 1 narrowed and 1 blocked bronchus,cavity in 3 cases(37.5%),necrosis in 1 case(12.5%),average arterial phase enhancement of the lesion 26.2HU,average vein phase enhancement of the lesion is 36HUand the CT changes in the surrounding areas are ground glass opacity is seen in 1 case(12.5%),consolidation in 7 cases(87.5%),peribronchovascular opacity no cases,bronchiectasis in 1 case(12.5%),nodule no cases,lymph node enlargement in 2 cases(25%).By comparing and analyzing the two groups of cases in clinical data and CT performances,we found that the mean age of the lung cancer group(63.42±10.69years old)was higher than that of organizing pneumonia group(51.38±12.83 years old),and the difference had statistical significance(P<0.05).The ratio of cough,spiculation sign,ground glass opacity,peribronchovascular opacity,airspace nodule and lymph node in lung cancer group is higher than that in organizing pneumonia group,and the difference had statistical significance(P<0.05).At the same time,the ratio of dyspnea,chest pain and contrast enhancement of vein phase was higher in organizing pneumonia group,and the difference had statistical significance(P<0.05).Other CT performances had no statistical significance(P>0.05).Conclusion:Careful analysis of CT manifestation,distribution and clinical features can help to distinguish between focal organizing pneumonia and lung cancer.