title: Whole-Body Computed Tomography-Based Body Mass and Body Fat Quantification: A Comparison to Hydrostatic Weighing and Air Displacement Plethysmography.
abstract: OBJECTIVE
  We correlate and evaluate the accuracy of accepted anthropometric methods of percent body fat (%BF) quantification, namely, hydrostatic weighing (HW) and air displacement plethysmography (ADP), to 2 automatic adipose tissue quantification methods using computed tomography (CT).
  
  
  METHODS
  Twenty volunteer subjects (14 men, 6 women) received head-to-toe CT scans. Hydrostatic weighing and ADP were obtained from 17 and 12 subjects, respectively. The CT data underwent conversion using 2 separate algorithms, namely, the Schneider method and the Beam method, to convert Hounsfield units to their respective tissue densities. The overall mass and %BF of both methods were compared with HW and ADP.
  
  
  RESULTS
  When comparing ADP to CT data using the Schneider method and Beam method, correlations were r = 0.9806 and 0.9804, respectively. Paired t tests indicated there were no statistically significant biases. Additionally, observed average differences in %BF between ADP and the Schneider method and the Beam method were 0.38% and 0.77%, respectively. The %BF measured from ADP, the Schneider method, and the Beam method all had significantly higher mean differences when compared with HW (3.05%, 2.32%, and 1.94%, respectively).
  
  
  CONCLUSIONS
  We have shown that total body mass correlates remarkably well with both the Schneider method and Beam method of mass quantification. Furthermore, %BF calculated with the Schneider method and Beam method CT algorithms correlates remarkably well with ADP. The application of these CT algorithms have utility in further research to accurately stratify risk factors with periorgan, visceral, and subcutaneous types of adipose tissue, and has the potential for significant clinical application.
authors.affiliation: From the *Department of Physiology and Developmental Biology, Brigham Young University, Provo UT; †Department Health Sciences, George Washington University, Washington, DC; ‡Department of Computer Science, Utah Valley University, Orem, UT; §Novarad, American Fork, UT; ∥Department of Mathematics, Utah Valley University, Orem, UT; ¶Exercise Science/Outdoor Recreation, Utah Valley University, Orem, UT; and #Department of Radiology, University of California San Diego, San Diego, CA.
authors.forename: Jacob T
authors.initials: JT
authors.lastname: Gibby
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Njeru
authors.forename: Steve T
authors.initials: ST
authors.lastname: Cvetko
authors.forename: Eric L
authors.initials: EL
authors.lastname: Heiny
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Creer
authors.forename: Wendell A
authors.initials: WA
authors.lastname: Gibby
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000328:Adult; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*