1. Department of Respiratory Diseases, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, P.R. China
2. Department of Medical Imaging and Nuclear Medicine, Shandong University, Jinan, Shandong 250014, P.R. China
3. Department of Respiratory Medicine, The First People's Hospital of Jining, Jining, Shandong 272011, P.R. China
4. Department of Medical Research Center, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong 250014, P.R. China
5. Department of Respiratory Diseases, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong 250014, P.R. China