Use of MRI and PET for Assessing Disease Activity in Takayasu's Arteritis

Takayasu's arteritis is a rare inflammatory disease that affects the aorta and its branches. The disease is much more common in females than in males, and disease onset typically occurs between the ages of 15 and 30. People with this disease often experience general discomfort, fatigue, fever, night sweats, weight loss, and joint pain. In the late stages of the disease, weak arterial walls may lead to aneurysms. Many patients do not exhibit any visible symptoms until this point, however. Because many people with Takayasu's arteritis do not have overt disease symptoms, the assessment of disease activity is difficult. Laboratory tests can help, but are often unreliable. Novel approaches to assessing disease activity are urgently needed to enhance and facilitate research on Takayasu's arteritis. This study will determine the effectiveness of combination positron emission tomography/computed axial tomography (PET/CT) in assessing disease activity in people with Takayasu's arteritis. Participants in this study will enroll while their disease is active. The first PET/CT scan will take place upon study entry, while there is active disease. Participants will have a second PET/CT scan 3 months later, and a third scan 3 months after that if there is still active disease present. Participants will have a maximum of 3 scans unless a scan needs to be repeated because of technical failures, though this does not often happen. If there is no active disease at the time of the second scan, a third scan will not be done. All PET/CT scans will be scheduled within 10 days of participants' routine MRI scans. This study will not require any follow-up visits.