E1813. A Multimodality Review of Large Vessel Vasculitis: Protocol, Pathologies, Follow-up, and Pitfalls
  1. Megan Mercer; Medical University of South Carolina
  2. Saeed Elojeimy; Medical University of South Carolina
  3. Thomas McLaren; Vanderbilt University
  4. Lisa Blacklock; University of New Mexico
  5. Sherry Wang; Mayo Clinic Rochester
  6. Shaimaa Fadl; Virginia Commonwealth University
  7. Jonathan Revels; New York University
Large vessel vasculitides (LVV) are highly morbid ailments that primarily affect the aorta and its branches. The most common variants are Takayasu arteritis and giant cell arteritis, but there are more rare subtypes such as Behcet’s disease and IgG4-related vasculitis. Imaging, in conjunction with biomarkers, is essential to an expedient diagnosis, as clinical presentation frequently varies. Initial diagnosis is not the only concern. Many patients have recurrent active disease despite treatment, so radiologists must be able to protocol an appropriate study and recognize both de-novo and recurrent cases.

Educational Goals / Teaching Points
The goal of this presentation is to present a concise summary of the radiologist’s role in the evaluation of large cell vasculitis. A multimodality compilation of cases will be presented, highlighting acquisition protocols and disease features on CT, MRI, and PET/CT. Pitfalls of diagnosis and mimickers of large cell vasculitis will be reviewed, and we will instruct the reader on how to recognize and avoid pitfalls. As many patients have been previously treated for vasculitis, this presentation will also review assessment for treatment response on follow-up imaging.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The evaluation of vasculitis is performed utilizing multiple modalities such as PET/CT, MRI, and CT. Each modality requires its own specific protocol and has its own specific diagnostic criteria. There are also various mimics of vasculitis that can be seen on each of the different imaging modalities. It is essential to be cognizant of the various treatment stages with vasculitis patients, to diagnose de novo disease and evaluate treatment response.

Large vessel vasculitides are debilitating diseases with multiple complications. Radiologists should be aware of the radiologic features of LVV not only to raise concern for the disease when it is not yet known, but also to assist clinicians in establishing the diagnosis whenever it is suspected clinically. Radiologic follow-up for treatment response can be difficult and often requires close communication with the managing physician.