1. Department of Respiratory Medicine, The 940th hospital of Joint Logistics Support Force of People's Liberation Army, Lanzhou, China;
2. Department of Medical Imaging Center, Gansu Provincial Maternal and Child Care Hospital, Lanzhou, China;
3. Functional Examination Department, Gansu Provincial Maternal and Child Care Hospital, Lanzhou, China;
4. Nuclear Magnetic Resonance Chamber, Lanzhou University Second Hospital, Lanzhou, China