title: Age- and Level-Dependence of Fatty Infiltration in Lumbar Paravertebral Muscles of Healthy Volunteers.
abstract: OBJECTIVE
  Normative age-related decline in paravertebral muscle quality is important for reference to disease and risk identification in patients. We aimed to establish age- and vertebral level-dependence of paravertebral (multifidus and erector spinae) muscle volume and fat content in healthy adult volunteers.
  
  
  METHODS
  In this prospective study multifidus and erector spinae fat signal fraction and volume at lumbar levels L1-L5 were measured in 80 healthy volunteers (10 women and men per decade, 20-62 years of age) by 2-point Dixon 3T MR imaging. ANOVA with post hoc Bonferroni correction compared fat signal fraction and volume among subgroups. Pearson and Spearman analysis were used for correlations (P < .05).
  
  
  RESULTS
  Fat signal fraction was higher in women (17.8% ± 10.7%) than men (14.7% ± 7.8%; P < .001) and increased with age. Multifidus and erector spinae volume was lower in women (565.4 ± 83.8 cm(3)) than in men (811.6 ± 98.9 cm(3); P < .001) and was age-independent. No differences in fat signal fraction were shown between the right and left paravertebral muscles or among the L1, L2, and L3 lumbar levels. The fat signal fraction was highest at L5 (women, 31.9% ± 9.3%; men, 25.7% ± 8.0%; P < .001). The fat signal fraction at L4 correlated best with total lumbar fat signal fraction (women, r = 0.95; men, r = 0.92, P < .001). Total fat signal fraction was higher in the multifidus compared with erector spinae muscles at L1-L4 for both sexes (P < .001).
  
  
  CONCLUSIONS
  Lumbar paravertebral muscle fat content increases with aging, independent of volume, in healthy volunteers 20-62 years of age. Women, low lumbar levels, and the multifidus muscle are most affected. Further study examining younger and older subjects and the functional impact of fatty infiltrated paravertebral muscles are warranted.
authors.affiliation: From the Centre for Health Sciences (R.J.C., J.M.E.), Zurich University of Applied Sciences, Winterthur, Switzerland Faculty of Health Professions (R.J.C.), Curtin University, Perth, Australia rebecca.crawford@zhaw.ch.
authors.forename: R J
authors.identifier: http://orcid.org/0000-0001-9153-6684
authors.initials: RJ
authors.lastname: Crawford
authors.affiliation: Institute of Diagnostic and Interventional Radiology (L.F., D.N., M.A.F., M.M., E.J.U.), University Hospital and University of Zurich, Zurich, Switzerland.
authors.forename: L
authors.identifier: http://orcid.org/0000-0003-0574-5127
authors.initials: L
authors.lastname: Filli
authors.affiliation: From the Centre for Health Sciences (R.J.C., J.M.E.), Zurich University of Applied Sciences, Winterthur, Switzerland Feinberg School of Medicine (J.M.E.), Northwestern University, Chicago, Illinois School of Health and Rehabilitation Sciences (J.M.E.), University of Queensland, Brisbane, Australia.
authors.forename: J M
authors.identifier: http://orcid.org/0000-0002-8890-6012
authors.initials: JM
authors.lastname: Elliott
authors.affiliation: Institute of Diagnostic and Interventional Radiology (L.F., D.N., M.A.F., M.M., E.J.U.), University Hospital and University of Zurich, Zurich, Switzerland.
authors.forename: D
authors.identifier: http://orcid.org/0000-0003-4128-5201
authors.initials: D
authors.lastname: Nanz
authors.affiliation: Institute of Diagnostic and Interventional Radiology (L.F., D.N., M.A.F., M.M., E.J.U.), University Hospital and University of Zurich, Zurich, Switzerland.
authors.forename: M A
authors.identifier: http://orcid.org/0000-0002-6753-124X
authors.initials: MA
authors.lastname: Fischer
authors.affiliation: Institute of Diagnostic and Interventional Radiology (L.F., D.N., M.A.F., M.M., E.J.U.), University Hospital and University of Zurich, Zurich, Switzerland Institute of Diagnostic Radiology (M.M.), University Hospital Santa Maria della Misericordia, Udine, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-3923-8115
authors.initials: M
authors.lastname: Marcon
authors.affiliation: Institute of Diagnostic and Interventional Radiology (L.F., D.N., M.A.F., M.M., E.J.U.), University Hospital and University of Zurich, Zurich, Switzerland.
authors.forename: E J
authors.identifier: http://orcid.org/0000-0002-8698-1780
authors.initials: EJ
authors.lastname: Ulbrich
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000254:growth & development / Q000473:pathology*; D000328:Adult; D000375:Aging / Q000473:pathology; D064131:Back Muscles / Q000000981:diagnostic imaging / Q000254:growth & development / Q000473:pathology*; D015992:Body Mass Index; D017097:Electric Impedance; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017116:Low Back Pain / Q000000981:diagnostic imaging; D008161:Lumbosacral Region / Q000000981:diagnostic imaging / Q000254:growth & development / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012727:Sex Characteristics; D051598:Whole Body Imaging; D055815:Young Adult