title: Fatty liver disease in severe obese patients: diagnostic value of abdominal ultrasound.
abstract: OBJECTIVE
  To evaluate the sensitivity and specificity of abdominal ultrasound (US) for the diagnosis of hepatic steatosis in severe obese subjects and its relation to histological grade of steatosis.
  
  
  METHODS
  A consecutive series of obese patients, who underwent bariatric surgery from October 2004 to May 2005, was selected. Ultrasonography was performed in all patients as part of routine preoperative time and an intraoperative wedge biopsy was obtained at the beginning of the bariatric surgery. The US and histological findings of steatosis were compared, considering histology as the gold standard.
  
  
  RESULTS
  The study included 105 patients. The mean age was 37.2+/-10.6 years and 75.2% were female. The histological prevalence of steatosis was 89.5%. The sensitivity and specificity of US in the diagnosis of hepatic steatosis were, respectively, 64.9% (95% CI: 54.9-74.3) and 90.9% (95% CI: 57.1-99.5). The positive predictive value and negative predictive value were, respectively, 98.4% (95% CI: 90.2-99.9) and 23.3% (95% CI: 12.3-39.0). The presence of steatosis on US was associated to advanced grades of steatosis on histology (P=0.016).
  
  
  CONCLUSIONS
  Preoperative abdominal US in our series has not shown to be an accurate method for the diagnosis of hepatic steatosis in severe obese patients. Until another non-invasive method demonstrates better sensitivity and specificity values, histological evaluation may be recommended to these patients undergoing bariatric surgery.
authors.affiliation: Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Avenida Tancredo Neves, Ed. Salvador Trade Center, Torre Norte-Sala 717, Salvador, Bahia 41830-020, Brazil.
authors.forename: Alessandro
authors.initials: A
authors.lastname: de Moura Almeida
authors.forename: Helma Pinchemel
authors.initials: HP
authors.lastname: Cotrim
authors.forename: Daniel Batista Valente
authors.initials: DB
authors.lastname: Barbosa
authors.forename: Luciana Gordilho Matteoni
authors.initials: LG
authors.lastname: de Athayde
authors.forename: Adimeia Souza
authors.initials: AS
authors.lastname: Santos
authors.forename: Almir Galvão Vieira
authors.initials: AG
authors.lastname: Bitencourt
authors.forename: Luiz Antonio Rodrigues
authors.initials: LA
authors.lastname: de Freitas
authors.forename: Adriano
authors.initials: A
authors.lastname: Rios
authors.forename: Erivaldo
authors.initials: E
authors.lastname: Alves
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000328:Adult; D050110:Bariatric Surgery; D001706:Biopsy; D005234:Fatty Liver / Q000150:complications* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications* / Q000601:surgery; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography