title: Calf muscle involvement in Becker muscular dystrophy: when size does not matter.
abstract: BACKGROUND
  Calf hypertrophy is a common feature in Becker muscular dystrophy (BMD), and it is still debated to which extent fatty degeneration or true muscle hypertrophy account for it. We wanted to investigate the relative contribution of these two components using a simple image analysis approach and their possible correlation with disease severity.
  
  
  METHODS
  Twenty-nine BMD patients' MRI scans were analyzed. A semiquantitative visual score assessing fatty replacement of calf muscles (calf MRI score, CMS) was calculated and correlated with the cross sectional area (CSA) of lower leg posterior compartment muscles, digitally measured on acquired images.
  
  
  RESULTS
  The correlation between CSA and CMS was not significant. CMS in contrast correlated with disease severity (p<0.001) while CSA did not (p=0.969).
  
  
  CONCLUSIONS
  In BMD, a major contribution to calf hypertrophy is provided by real muscle hypertrophy rather than by fatty degeneration. CMS appears to be a potential surrogate marker of disease severity.
authors.affiliation: Institute of Neurology, Catholic University School of Medicine, Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Monforte
authors.affiliation: Pediatric Neurology Unit, Catholic University School of Medicine, Rome, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mercuri
authors.affiliation: Department of Radiology, Istituto Dermopatico dell'Immacolata, IRCCS, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Laschena
authors.affiliation: Institute of Neurology, Catholic University School of Medicine, Rome, Italy. Electronic address: ericci@rm.unicatt.it.
authors.forename: Enzo
authors.initials: E
authors.lastname: Ricci
authors.affiliation: Don Carlo Gnocchi Onlus Foundation, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Tasca
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D006984:Hypertrophy / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D007866:Leg / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000473:pathology*; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Becker muscular dystrophy; Calf hypertrophy; Cross sectional area; Disease severity; Fatty degeneration; Magnetic resonance imaging