title: Assessment of skeletal muscle mass in critically ill patients: considerations for the utility of computed tomography imaging and ultrasonography.
abstract: OBJECTIVE
  Low muscularity and skeletal muscle atrophy are commonly exhibited in critically ill patients and have major implications on patient outcomes. Typically, in the ICU, body composition is assessed through anthropometrics or bioelectrical impedance analysis, but these modalities cannot specifically quantify skeletal muscle; thus, we evaluate the merits and challenges of using computed tomography (CT) and ultrasonography to specifically measure skeletal muscle in the ICU.
  
  
  RESULTS
  CT-based cut points have been used to identify critically ill patients with low muscle mass, and low muscularity associates with poor clinical outcomes and function. Ultrasonography is emerging as a useful tool to quantify skeletal muscle loss and degradation in architecture, as well as prospectively track changes in these parameters over time. Rates of muscle atrophy and changes in muscle architecture has been quantified by ultrasonography and associated with poor clinical outcomes, but identification of critically ill patients with low muscularity is still in its infancy.
  
  
  CONCLUSIONS
  CT imaging and ultrasonography require additional comprehensive validations against accurate measures of whole body muscle mass. As these validations begin to emerge, there will be a need to translate this knowledge into a simple tool that clinicians can apply as part of routine care.
authors.affiliation: Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Paris
authors.forename: Marina
authors.initials: M
authors.lastname: Mourtzakis
mesh_terms: D001823:Body Composition; D016638:Critical Illness; D006801:Humans; D007362:Intensive Care Units; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000517:prevention & control; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed