title: The significance of fat and muscle areas in the lumbar paraspinal space: a CT study.
abstract: OBJECTIVE
  The object of this study was to determine the significance of fat deposition and muscle dimensions on CT in the unoperated lumbar paraspinal space.
  
  
  METHODS
  Fifty patients were prospectively studied. Paraspinal fat (PSF) and muscle (PSM) areas were correlated with various demographic and anatomical variables in patients with and without low back pain. The fat and muscle areas were derived from a standard CT image using a thresholding technique.
  
  
  RESULTS
  Regression equations indicated that the total amount of PSF increases with age and subcutaneous fat area. The PSM area decreases with age. There was no correlation with the other variables examined.
  
  
  CONCLUSIONS
  We conclude that PSF deposition and PSM dimensions on CT are related to patient age and the amount of subcutaneous fat. Paraspinal fat deposition is not a sign of muscle atrophy, and neither parameter is related to low back pain symptoms. Therefore, in patients who have not undergone spinal surgery, PSF and PSM areas are not of clinical or functional significance.
authors.affiliation: Department of Radiology, St. Vincent's Hospital, Dublin, Ireland.
authors.forename: R F
authors.initials: RF
authors.lastname: McLoughlin
authors.forename: E M
authors.initials: EM
authors.lastname: D'Arcy
authors.forename: M M
authors.initials: MM
authors.lastname: Brittain
authors.forename: O
authors.initials: O
authors.lastname: Fitzgerald
authors.forename: J B
authors.initials: JB
authors.lastname: Masterson
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005205:Fascia / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000000981:diagnostic imaging* / Q000473:pathology; D011446:Prospective Studies; D013382:Subtraction Technique; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods