Pulmonary Vasculitis

Abstract

Vasculitis refers to inflammation of blood vessel walls that results in vascular wall destruction and ischemic injury to affected organs. Common vasculitides discussed herein include Takayasu arteritis (TAK), giant cell arteritis (GCA), antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides such as granulomatosis with polyangiitis (GPA) and eosinophilic granulomatosis with polyangiitis (EGPA), and anti-glomerular basement membrane (anti-GBM) disease or Goodpasture syndrome. Vasculitides are further subcategorized depending of the size of the predominantly affected vessels: large, medium and small vessel vasculitis. The affected vessel size strongly influences the clinical and imaging manifestations of the disease. Intrathoracic involvement is more common in small and large vessel vasculitides. Diffuse alveolar hemorrhage (DAH), a common manifestation of vasculitis, is considered a syndrome rather than a specific entity and will be discussed in this chapter. However, it should be noted that DAH may also result from non-vasculitic etiologies. The work up and diagnosis of patients with primary vasculitides is challenging and requires close collaboration between the clinician, the radiologist and the pathologist. Radiographic abnormalities are non specific or may be absent. CT and MRI are the imaging modalities of choice for the evaluation and follow up of these patients, and should be considered despite normal radiographics.