title: Giant cell arteritis: diagnostic accuracy of MR imaging of superficial cranial arteries in initial diagnosis-results from a multicenter trial.
abstract: OBJECTIVE
  To assess the diagnostic accuracy of contrast material-enhanced magnetic resonance (MR) imaging of superficial cranial arteries in the initial diagnosis of giant cell arteritis ( GCA giant cell arteritis ).
  
  
  METHODS
  Following institutional review board approval and informed consent, 185 patients suspected of having GCA giant cell arteritis were included in a prospective three-university medical center trial. GCA giant cell arteritis was diagnosed or excluded clinically in all patients (reference standard [final clinical diagnosis]). In 53.0% of patients (98 of 185), temporal artery biopsy ( TAB temporal artery biopsy ) was performed (diagnostic standard [ TAB temporal artery biopsy ]). Two observers independently evaluated contrast-enhanced T1-weighted MR images of superficial cranial arteries by using a four-point scale. Diagnostic accuracy, involvement pattern, and systemic corticosteroid ( sCS systemic corticosteroid ) therapy effects were assessed in comparison with the reference standard (total study cohort) and separately in comparison with the diagnostic standard TAB temporal artery biopsy ( TAB temporal artery biopsy subcohort). Statistical analysis included diagnostic accuracy parameters, interobserver agreement, and receiver operating characteristic analysis.
  
  
  RESULTS
  Sensitivity of MR imaging was 78.4% and specificity was 90.4% for the total study cohort, and sensitivity was 88.7% and specificity was 75.0% for the TAB temporal artery biopsy subcohort (first observer). Diagnostic accuracy was comparable for both observers, with good interobserver agreement ( TAB temporal artery biopsy subcohort, κ = 0.718; total study cohort, κ = 0.676). MR imaging scores were significantly higher in patients with GCA giant cell arteritis -positive results than in patients with GCA giant cell arteritis -negative results ( TAB temporal artery biopsy subcohort and total study cohort, P < .001). Diagnostic accuracy of MR imaging was high in patients without and with sCS systemic corticosteroid therapy for 5 days or fewer (area under the curve, ≥0.9) and was decreased in patients receiving sCS systemic corticosteroid therapy for 6-14 days. In 56.5% of patients with TAB temporal artery biopsy -positive results (35 of 62), MR imaging displayed symmetrical and simultaneous inflammation of arterial segments.
  
  
  CONCLUSIONS
  MR imaging of superficial cranial arteries is accurate in the initial diagnosis of GCA giant cell arteritis . Sensitivity probably decreases after more than 5 days of sCS systemic corticosteroid therapy; thus, imaging should not be delayed. Clinical trial registration no. DRKS00000594 .
authors.affiliation: From the Department of Diagnostic, Interventional, and Pediatric Radiology, Inselspital-Bern University Hospital, Bern, Switzerland (T.K.); Departments of Radiology-Medical Physics (J.G.), Neurology (M.R.), and Rheumatology and Clinical Immunology (P.V.), University Medical Center Freiburg, Freiburg, Germany; Departments of Diagnostic Radiology (M.B.) and Ophthalmology (D.D.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany; Department of Ophthalmology, University Hospital Freiburg, Freiburg, Germany (T.N., S.H.); Institute of Pathology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany (K.H.); and Department of Radiology, University of Würzburg, Würzburg, Germany (T.A.B.).
authors.forename: Thorsten
authors.initials: T
authors.lastname: Klink
authors.forename: Julia
authors.initials: J
authors.lastname: Geiger
authors.forename: Marcus
authors.initials: M
authors.lastname: Both
authors.forename: Thomas
authors.initials: T
authors.lastname: Ness
authors.forename: Sonja
authors.initials: S
authors.lastname: Heinzelmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Reinhard
authors.forename: Konstanze
authors.initials: K
authors.lastname: Holl-Ulrich
authors.forename: Dirk
authors.initials: D
authors.lastname: Duwendag
authors.forename: Peter
authors.initials: P
authors.lastname: Vaith
authors.forename: Thorsten Alexander
authors.initials: TA
authors.lastname: Bley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D013700:Giant Cell Arteritis / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013699:Temporal Arteries / Q000473:pathology*
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol