Relationship Between the Activity of Rheumatoid Arthritis and Lymph Node Morphology and Lymphatics Drainage

Inclusion Criteria: 1. Patients fulfilling the classification criteria of American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2009 (scores more than 6 points) 2. Health participants normal in the test of blood/urine/stool routine, liver and kidney functions, electrocardiogram and without obvious medical history 3. Age 18 to 65 years 4. Fulling understood the whole trial and written informed consent. Exclusion Criteria: Participants will be excluded when they combined with: 1. other types of autoimmune diseases such as ankylosing spondylitis, systemic lupus erythematosus, scleroderma, etc., 2. lymphatic system disorders, such as lymphoma, lymphangitis and lymphatic edema due to lymphatic flow disorders, 3. disorders that effect the circulation of lymph or blood vessels such as hemangiomas, 4. tumors or cancer, 5. operation history within a year, such as joint orthopedics, tumor resection, etc., 6. allergies or allergic to iodine, or radioactive iodine treatment within the last year, 7. with metal objects inside, such as pacemakers or nails, 8. the skin for the ultrasound inspection not intact such as eczema,ulceration, etc., 9. lactation or pregnancy women or preparation to be pregnant within the next half year, 10. without whole limbs to inspect, 11. mania, depression or other mental disorder 12. medical disorders such as diabetes, hypertension or hyperlipidemia, etc., 13. a history of infectious diseases such as tuberculosis, hepatitis B or HIV, etc., 14. a history of drug abuse such as opioid analgesics, sedative-hypnotics or alcohol abuse, etc., 15. severe liver or kidney dysfunction (Alanine Aminotransferase(ALT) or Aspartate Aminotransferase(AST) two times higher than the upper limit of normal, serum creatinine levels more than two times the upper limit of normal); 16. poor compliance.