ACR Appropriateness Criteria® Noncerebral Vasculitis

Area of Science:

• Rheumatology and Radiology
• Vascular Inflammation
• Diagnostic Imaging

Background:

• Noncerebral vasculitis encompasses a spectrum of noninfectious inflammatory disorders affecting blood vessels.
• Classification of vasculitides is based on vessel size: large-vessel, medium-vessel, and small-vessel types.
• This document focuses on diagnostic imaging strategies for large-vessel and medium-vessel vasculitis.

Framework:

• Imaging is paramount for diagnosing vasculitis due to challenges with vessel biopsy.
• Computed Tomography Angiography (CTA) and Magnetic Resonance Angiography (MRA) offer detailed anatomical insights into vessel walls for large-vessel vasculitis.
• Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography (FDG-PET/CT) provides functional assessment by detecting inflammatory cell activity.

Implementation:

• Invasive arteriography remains a diagnostic option for medium-vessel vasculitis, considering vessel size.
• High-resolution CTA is effective in identifying small aneurysms characteristic of medium-vessel vasculitis.
• The American College of Radiology Appropriateness Criteria guide imaging and treatment decisions, incorporating literature review and expert consensus.

Implications:

• Accurate imaging modalities are essential for timely and appropriate diagnosis of large-vessel and medium-vessel vasculitis.
• The integration of anatomical and functional imaging enhances diagnostic confidence.
• Evidence-based guidelines, supplemented by expert opinion, ensure optimal patient care pathways.