9Marcin Szkudlarek,Eva Narvestad,Mette Klarlund,et al.Ultra-sonography of the Metatarsophalangeal Joints in Rheumatoid Arthritis.Arthritis & Rheumatism,2004,50(7):2103-2112.
10Bowen CJ,Dewbury K,Sampson M,et al.Musculoskeletal ultrasound imaging of the plantar forefoot in patients with rheumatoid arthritis:inter-observer agreement between a podiatrist and a radiologist.J Foot Ankle Res,2008,1(1):5.