Inclusion Criteria:  Informed consent Age 18-70 years old Diagnosed with TAO.  Exclusion Criteria:  Contraindications to immunosuppressive agents. Patients with HIV, Hepatitis B or C, Tuberculosis or other active significant infection. Patients with severe chronic diseases in heart, lung, kidney and liver, which make it not tolerant to immunosuppressive agents. Patients have contraindications of MRI(metal pacemaker, fake teeth, foreign body and other materials which will disturb the examination).