title: Magnetic resonance angiography in extracranial giant cell arteritis.
abstract: BACKGROUND
  Noninvasive diagnosis of giant cell arteritis (GCA) remains challenging, particularly with regard to evaluation of extracranial arterial disease.
  
  
  OBJECTIVE
  The objective of the study was to retrospectively review extracranial involvement in patients with GCA and/or polymyalgia rheumatica (PMR), evaluated with magnetic resonance imaging (MRI), especially 3-dimensional contrast-enhanced magnetic resonance angiography images of the aortic arch and its branches.
  
  
  METHODS
  Clinical information, biopsy status, and MRI examinations of 28 patients with GCA/PMR were reviewed. Patient images were mixed randomly with 20 normal control images and were independently reviewed by 2 radiologists. Interobserver agreement for detection of arterial stenosis was determined by the k coefficient.
  
  
  RESULTS
  Both readers described vascular alterations in keeping with extracranial GCA in 19 of 28 patients (67%) with good interobserver agreement (k = 0.73) and with even higher agreement on diagnosing nonocclusive versus occlusive disease (k = 1.00). The most common lesions were bilateral axillary stenosis or obstructions, observed by both readers in 8 patients (28%). Among the 19 patients with magnetic resonance angiography lesions in the subclavian/axillary arteries, 12 (75%) had biopsy-proven GCA, but only 5 (41%) of these patients had clinical features of large artery disease.
  
  
  CONCLUSIONS
  In our series review, MRI could provide accurate information on involvement of the aortic arch and its branches in extracranial GCA, depicting different degrees of stenosis. Our analysis also illustrates that occult large artery vasculitis should be considered in patients without biopsy-proven GCA, patients with classic GCA but without clinical signs of large artery disease, and in patients initially diagnosed as having PMR.
authors.affiliation: Department of Radiology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil. marcelk46@yahoo.com.br
authors.forename: Marcel
authors.initials: M
authors.lastname: Koenigkam-Santos
authors.forename: Puneet
authors.initials: P
authors.lastname: Sharma
authors.forename: Bobby
authors.initials: B
authors.lastname: Kalb
authors.forename: John N
authors.initials: JN
authors.lastname: Oshinski
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Weyand
authors.forename: Jörg J
authors.initials: JJ
authors.lastname: Goronzy
authors.forename: Diego R
authors.initials: DR
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D013700:Giant Cell Arteritis / Q000175:diagnosis*; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011111:Polymyalgia Rheumatica / Q000175:diagnosis*; D011859:Radiography; D012189:Retrospective Studies; D014657:Vasculitis / Q000175:diagnosis