title: Dynamic ASL and T2-weighted MRI in exercising calf muscle at 7 T: a feasibility study.
abstract: OBJECTIVE
  The aim of this study was to develop a measurement protocol for noninvasive simultaneous perfusion quantification and T2 *-weighted MRI acquisition in the exercising calf muscle at 7 Tesla.
  
  
  METHODS
  Using a nonmagnetic ergometer and a dedicated in-house built calf coil array, dynamic pulsed arterial spin labeling (PASL) measurements with a temporal resolution of 12 s were performed before, during, and after plantar flexion exercise in 16 healthy volunteers.
  
  
  RESULTS
  Postexercise peak perfusion in gastrocnemius muscle (GAS) was 27 ± 16 ml/100g/min, whereas in soleus (SOL) and tibialis anterior (TA) muscles it remained at baseline levels. T2 *-weighted and ASL time courses in GAS showed comparable times to peak of 161 ± 72 s and 167 ± 115 s, respectively. The T2 *-weighted signal in the GAS showed a minimum during exercise (88 ± 6 % of the baseline signal) and a peak during the recovery (122 ± 9%), whereas in all other muscles only a signal decrease was observed (minimum 91 ± 6% in SOL; 87 ± 8% in TA).
  
  
  CONCLUSIONS
  We demonstrate the feasibility of dynamic perfusion quantification in skeletal muscle at 7 Tesla using PASL. This may help to better investigate the physiological processes in the skeletal muscle and also in diseases such as diabetes mellitus and peripheral arterial disease.
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria; MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.
authors.forename: Kiril
authors.initials: K
authors.lastname: Schewzow
authors.forename: Georg Bernd
authors.initials: GB
authors.lastname: Fiedler
authors.forename: Martin
authors.initials: M
authors.lastname: Meyerspeer
authors.forename: Sigrun
authors.initials: S
authors.lastname: Goluch
authors.forename: Elmar
authors.initials: E
authors.lastname: Laistler
authors.forename: Michael
authors.initials: M
authors.lastname: Wolzt
authors.forename: Ewald
authors.initials: E
authors.lastname: Moser
authors.forename: Albrecht Ingo
authors.initials: AI
authors.lastname: Schmid
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007866:Leg; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: 7 Tesla; T2*; arterial spin labeling; exercise; perfusion; plantar flexion; skeletal muscle