title: Ultrasound features of tophi in chronic tophaceous gout.
abstract: OBJECTIVE
  To describe the different and lesser-known ultrasound features of tophi in chronic tophaceous gout.
  
  
  METHODS
  Ultrasound images of 138 affected areas were analyzed from 31 patients with gout, using high-quality broadband linear transducers (frequency range of 8-14 MHz). Tophi were classified relative to echogenicity, echotexture, contours, number and the presence or absence of hypoechoic halo. The duration of illness was correlated with the presence of calcifications in tophi.
  
  
  RESULTS
  Hyperechoic tophi were seen in 133 areas (96.3%); these were most frequently hyperechoic and heterogeneous (37.6%) or hyperechoic and heterogeneous with calcification (32.6%). Contours were found to be poorly defined in 115 (83.3%) areas. Multiple grouped tophi were seen in 85 areas (61.6%) and 50 areas (36.2%) had individual tophi. In 77 examined areas (55.8%), there was a hypoechoic halo around the tophi. There was no correlation between illness duration and presence of calcifications on tophi.
  
  
  CONCLUSIONS
  Tophi are generally hyperechoic, heterogeneous, with poorly defined contours, multiple grouped and surrounded by an anechoic halo. Individual tophus and the absence of association between illness duration and the presence of calcification are newly described features. This study of tophaceous gout by ultrasound may contribute to the diagnostic elucidation of patients with clinically atypical gout and show its diverse characteristic forms of presentation.
authors.affiliation: Department of Diagnostic Imaging, Federal University of São Paulo, São Paulo, Brazil. lofernan@uol.com.br
authors.forename: Eloy
authors.initials: E
authors.lastname: de Ávila Fernandes
authors.forename: Edson S
authors.initials: ES
authors.lastname: Kubota
authors.forename: Gabriel B
authors.initials: GB
authors.lastname: Sandim
authors.forename: Sônia A V
authors.initials: SA
authors.lastname: Mitraud
authors.forename: Antonio J L
authors.initials: AJ
authors.lastname: Ferrari
authors.forename: Artur R C
authors.initials: AR
authors.lastname: Fernandes
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006073:Gout / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*