title: Fast measurement of the quadriceps femoris muscle transverse relaxation time at high magnetic field using segmented echo-planar imaging.
abstract: To assess and validate a technique for transverse relaxation time (T2) measurements of resting and recovering skeletal muscle following exercise with a high temporal resolution and large volume coverage using segmented spin-echo echo-planar imaging (sSE-EPI).
  
  
  
  Experiments were performed on a 3T magnetic resonance imaging (MRI) scanner using a multislice sSE-EPI technique applied at different echo times (TEs). T2measurements were first validated in vitro in calibrated T2phantoms (range: 25-152 ms) by comparing sSE-EPI, standard spin-echo (SE), and multislice multiecho (MSME) techniques (using a fitting procedure or a 2-TEs calculation). In vivo measurements of resting T2quadriceps femoris (QF) muscle were performed with both sSE-EPI and MSME sequences. Finally, sSE-EPI was used to quantify T2changes in recovering muscle after an exercise.
  
  
  
  T2values measured in vitro with sSE-EPI were similar to those assessed with SE (P > 0.05). In vitro and in vivo T2measurements obtained with sSE-EPI were independent of the T2determination procedure (P > 0.05). In contrast, both in vitro and in vivo T2values derived from MSME were significantly different when using 2-TEs calculation as compared to the fitting procedure (P < 0.05). sSE-EPI allowed the detection of increased T2values in the QF muscle immediately after exercise (+14 ± 9%), while lower T2values were recorded less than 2 min afterwards (P < 0.05).
  
  
  
  sSE-EPI sequence is a relevant method to monitor exercise-induced T2changes of skeletal muscles over large volume coverage and to detect abnormal patterns of muscle activation.
  
  
  
  1 J. Magn. Reson. Imaging 2017;45:356-368.
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Fouré
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Duhamel
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Vilmen
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.
authors.forename: David
authors.initials: D
authors.lastname: Bendahan
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.|Université de Nantes, Laboratoire "Motricité, Interactions, Performance,", Nantes, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Jubeau
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR, 7339, Marseille, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Gondin
mesh_terms: D000328:Adult; D000465:Algorithms; D017352:Echo-Planar Imaging / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D060526:Magnetic Fields; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D009929:Organ Size / Q000502:physiology; D052097:Quadriceps Muscle / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: MRI; T2; exercise; skeletal muscle; spin-echo sequence