title: A low-cost Mr compatible ergometer to assess post-exercise phosphocreatine recovery kinetics.
abstract: OBJECTIVE
  To develop a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems to reliably quantify metabolic parameters in human lower leg muscle using phosphorus magnetic resonance spectroscopy.
  
  
  METHODS
  We constructed an MR compatible ergometer using commercially available materials and elastic bands that provide resistance to movement. We recruited ten healthy subjects (eight men and two women, mean age ± standard deviation: 32.8 ± 6.0 years, BMI: 24.1 ± 3.9 kg/m2). All subjects were scanned on a 7 T whole-body magnet. Each subject was scanned on two visits and performed a 90 s plantar flexion exercise at 40% maximum voluntary contraction during each scan. During the first visit, each subject performed the exercise twice in order for us to estimate the intra-exam repeatability, and once during the second visit in order to estimate the inter-exam repeatability of the time constant of phosphocreatine recovery kinetics. We assessed the intra and inter-exam reliability in terms of the within-subject coefficient of variation (CV).
  
  
  RESULTS
  We acquired reliable measurements of PCr recovery kinetics with an intra- and inter-exam CV of 7.9% and 5.7%, respectively.
  
  
  CONCLUSIONS
  We constructed a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems, which allowed us to quantify reliably PCr recovery kinetics in lower leg muscle using31P-MRS.
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Niels D
authors.initials: ND
authors.lastname: Naimon
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Walczyk
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Khegai
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Che
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Leeor
authors.initials: L
authors.lastname: Alon
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Ravinder R
authors.initials: RR
authors.lastname: Regatte
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Brown
authors.affiliation: Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA. prodromos.parasoglou@nyumc.org.|Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA. prodromos.parasoglou@nyumc.org.
authors.forename: Prodromos
authors.identifier: http://orcid.org/0000-0001-8512-6187
authors.initials: P
authors.lastname: Parasoglou
mesh_terms: D000328:Adult; D003362:Cost-Benefit Analysis; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005080:Exercise Test / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008657:Metabolic Clearance Rate; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010725:Phosphocreatine / Q000378:metabolism*; D020127:Recovery of Function / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010725:Phosphocreatine
keywords: Exercise; Human skeletal muscle; Magnetic resonance spectroscopy; Phosphorus