title: Quantitative ultrashort TE imaging of the short-T2components in skeletal muscle using an extended echo-subtraction method.
abstract: To introduce an ultrashort echo time (UTE) based method for quantitative mapping of short-T2signals in skeletal muscle (SKM) in the presence of fat, with the aim of monitoring SKM fibrosis.
  
  
  
  From a set of at least five UTE images of the same slice, a long- T2* map, a fat-fraction map, and a map of short-T2-signal fraction are extracted. The method was validated by numerical simulations and in vitro studies on collagen solutions. Finaly, the method was applied to image the short-T2signals in the leg of eight healthy volunteers.
  
  
  
  The imaged short-T2-signal fractions in the collagen solutions correlated with their respective collagen concentrations ( R=0.999,  P=0.009). Short-T2tissues such as cortical bone and fasciae were highlighted in the resulting short-T2fraction maps. A significant fraction of short-T2signal was systematically observed in the skeletal muscle of all of the subjects (4.5±1.2%).
  
  
  
  The proposed method allows the quantitative imaging of short-T2components in tissues containing fat. By also having the fat-fraction and T2* maps as outcomes, long-T2suppression is accomplished without requiring modifications to the basic UTE sequence. Although the hypersignal observed in the fasciae suggests that the short-T2signal observed in SKM might arise from interstitial connective tissue, further investigation is necessary to confirm this statement. Magn Reson Med 78:997-1008, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: NMR Laboratory, Institute of Myology, Pitié-Salpêtrière University Hospital, Paris, France.|CEA/DRF/I2BM/MIRCen, Fontenay aux Roses, France.
authors.forename: Ericky
authors.initials: E
authors.lastname: C A Araujo
authors.affiliation: NMR Laboratory, Institute of Myology, Pitié-Salpêtrière University Hospital, Paris, France.|CEA/DRF/I2BM/MIRCen, Fontenay aux Roses, France.
authors.forename: N
authors.initials: N
authors.lastname: Azzabou
authors.affiliation: CEA/DRF/I2BM/NeuroSpin/UNIRS, Gif Sur Yvette, France.
authors.forename: A
authors.initials: A
authors.lastname: Vignaud
authors.affiliation: IR4M UMR8081, CNRS, University of Paris-Sud, University of Paris-Saclay, Orsay, France.
authors.forename: G
authors.initials: G
authors.lastname: Guillot
authors.affiliation: NMR Laboratory, Institute of Myology, Pitié-Salpêtrière University Hospital, Paris, France.|CEA/DRF/I2BM/MIRCen, Fontenay aux Roses, France.
authors.forename: P G
authors.initials: PG
authors.lastname: Carlier
mesh_terms: D000328:Adult; D003094:Collagen / Q000737:chemistry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D013382:Subtraction Technique
chemical_list: D003094:Collagen
keywords: long-T2 suppression; quantitative imaging; short-T2 imaging; skeletal muscle fibrosis; ultrashort TE