title: Diagnostic validity of Doppler ultrasound in giant cell arteritis.
abstract: OBJECTIVE
  To assess the validity of Doppler ultrasound in the diagnosis of giant cell arteritis (GCA), using the American College of Rheumatology (ACR) criteria and biopsy and using as gold standard the patient's definitive clinical diagnosis.
  
  
  METHODS
  An observational, descriptive and analytical study of 451 consecutive patients with suspected GCA was conducted, and the clinical history and ultrasound findings of the patients were reviewed. The validity of ACR criteria, temporal arteritis biopsy (TAB) and Doppler ultrasound in the diagnosis of GCA was calculated using the final diagnosis of the doctor in charge as the gold standard.
  
  
  RESULTS
  The validity and security of the diagnostic tests used were as follows: ACR criteria had 65.37% sensitivity and 62.89% specificity; positive predictive value [PPV] 70%; negative predictive value [NPV] 57.82%, likelihood ratio [LR] + 1.7619 and LR - 0.5506. Doppler ultrasonography had 91.60% sensitivity and 95.83% specificity; PPV 96.62%; NPV 89.76%, LR + 21.81 and LR - 0.0876; TA biopsy 42.86% sensitivity and 100% specificity; PPV 100%; NPV 35.71% and LR - 0.5714.
  
  
  CONCLUSIONS
  The halo sign, especially if bilateral, is a strong predictor of GCA with a level of accuracy sufficient to recommend its introduction into clinical practice and, in our opinion, should be considered in future classification criteria sets.
authors.affiliation: University of Córdoba (UCO), Córdoba; and Rheumatology Department, University Hospital La Paz, Madrid, Spain. conchita.87.8@gmail.com.
authors.forename: I Concepción
authors.initials: IC
authors.lastname: Aranda-Valera
authors.affiliation: Rheumatology Department, University Hospital La Paz, Madrid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: García Carazo
authors.affiliation: Rheumatology Department, University Hospital La Paz, Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Monjo Henry
authors.affiliation: Rheumatology Department, University Hospital La Paz, Madrid, Spain.
authors.forename: Eugenio
authors.initials: E
authors.lastname: De Miguel Mendieta
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D013700:Giant Cell Arteritis / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013699:Temporal Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D018615:Ultrasonography, Doppler, Color