title: The role of ultrasonography in the evaluation of abdominal fat: analysis of technical and methodological issues.
abstract: OBJECTIVE
  Ultrasonography (US) is becoming popular for the assessment of adiposity, but no one has studied this tool in the light of its potential limitations. Our purpose was to investigate the impact of technical conditions on the evaluation of abdominal fat by US.
  
  
  METHODS
  Forty-five healthy males and 45 healthy females were consecutively enrolled in the study, randomly assigned to three groups equally distributed by sex, and examined accordingly to three technical points: fasting state (before and after meal [A]), breathing (expiration and inspiration [B]), and US equipment from different generations: 2003 and 1998 (C). Two blinded radiologists performed US in the these opposite conditions, acquiring five parameters representative of subcutaneous and visceral adiposity in two times. Student's t-test and Lin's correlation coefficient were used for statistical analysis to assess differences in the measures as well as in inter- and intra-observer agreements.
  
  
  RESULTS
  The maximum and the only statistically significant changes were observed for intra-abdominal fat thickness regarding fasting state and breathing (Δ% = 24.1 ± 21.3 and Δ% = 9.2 ± 20.4, respectively; P < .0001). Reproducibility and repeatability, especially for visceral fat, were proved more stable in the following conditions: fasting state, expiration, and newer machine (2003).
  
  
  CONCLUSIONS
  This article provides essential information and "range of confidence" for variations that can be expected from using different conditions in the measurement of abdominal adiposity by US to be carefully addressed as well as considered by US users and by researchers involving this technique in the field of body composition.
authors.affiliation: Department of Specialized, Diagnostic, and Experimental Medicine, University of Bologna, Sant'Orsola - Malpighi Hospital, Via G. Massarenti 9, 40138 Bologna, Italy; Diagnostic and Interventional Radiology, "Rizzoli" Orthopaedic Institute, Bologna, Italy. Electronic address: abazzo@inwind.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Bazzocchi
authors.forename: Giacomo
authors.initials: G
authors.lastname: Filonzi
authors.forename: Federico
authors.initials: F
authors.lastname: Ponti
authors.forename: Michele
authors.initials: M
authors.lastname: Amadori
authors.forename: Claudia
authors.initials: C
authors.lastname: Sassi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Salizzoni
authors.forename: Ugo
authors.initials: U
authors.lastname: Albisinni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Battista
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging*; D000465:Algorithms; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014463:Ultrasonography / Q000379:methods*
keywords: Body composition; adiposity; methods; reproducibility of results; ultrasonography