1. School of Mathematics and Statistics, Hubei University of Arts and Science, Xiangyang, Hubei 441000, China
2. Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, Hubei 441000, China
3. Medical College of China Three Gorges University, Yichang, Hubei 443002, China
4. Department of Gastroenterology, Xiangyang No. 1 People’s Hospital, Hubei University of Medicine, Xiangyang, Hubei 441000, China