Large vessel vasculitis (LVV) causes vascular inflammation, leading to serious complications such as aneurysm formation and stroke. It is difficult to identify the inflammation of the vessel wall by the current imaging methods, thus affecting the timing of treatment and selection of treatment options. Improved examination methods to determine disease activity are highly needed to guide treatment.

This study was designed to assess vascular wall inflammation in patients with large vessel vasculitis by positron emission tomography and magnetic resonance imaging (PET/MRA). The study has a 12-month follow-up period. After completing the baseline clinical assessment, laboratory test and PET/MRA assessment, the intervention protocol will be determined by clinicians. The patients will visit the clinic every 1-2 months according to their specific conditions. Clinical assessment, laboratory test and PET/MRA re-examination will be completed at 6 and 12 months after treatment.

Inclusion Criteria:

1. Clinically suspected or confirmed LVV and willing to undergo PET/MRA
2. Compliance with long-term follow-up
3. Sign informed consent.

Exclusion Criteria:

1. Patients with other serious cardiovascular and cerebrovascular diseases, malignant tumors, infectious diseases, severe renal insufficiency.
2. Severe mental disorders, severe claustrophobia unable to cooperate with the examination.
3. Patients equipped with cardiac pacemaker, artificial heart valve, ferromagnetic vascular clamp after vascular surgery, aneurysm clamp, artificial cochlea, insulin pump and other drug dosage control devices, steel nail plate and other metal internal fixation, artificial joint, electronic eye, artificial eye.
4. Allergic to contrast medium.
5. Pregnant or lactating women.

Withdrawal criteria:

1. Any exclusion criteria emerged during patient follow-up.
2. Voluntarily withdrew from the study.

Clinically suspected or confirmed LVV