title: Magnetization transfer effect on the creatine methyl resonance studied by CW off-resonance irradiation in human skeletal muscle on a clinical MR system.
abstract: Magnetization transfer (MT) between the mobile (MR-visible) spin pool and immobile (MR-invisible) spin pool of creatine (Cr) was studied on a clinical 1.5 T MR scanner in human skeletal muscle using continuous wave (CW) pre-irradiation as the saturation method for the immobile pool. For this purpose, only slight modifications to the MR system were made. A specially designed electronic circuit was used to couple a CW amplifier to the RF channel of the scanner. The CW pulse power (gammaB(2)/2pi) and pulse length were determined to be approximately 550 Hz and 3 s, respectively, for optimal signal attenuation of the Cr methyl signal. The bound Cr fraction in human gastrocnemius muscle was determined to be 0.4-1.3% using a two-pool exchange model function to describe the MT effect.
authors.affiliation: Department of Radiology, University Medical Center Nijmegen, Nijmegen, The Netherlands. k.renema@rad.umcn.nl
authors.forename: W Klaas Jan
authors.initials: WK
authors.lastname: Renema
authors.forename: Dennis W J
authors.initials: DW
authors.lastname: Klomp
authors.forename: Mariëlle E P
authors.initials: ME
authors.lastname: Philippens
authors.forename: Adrianus J
authors.initials: AJ
authors.lastname: van den Bergh
authors.forename: Bé
authors.initials: B
authors.lastname: Wieringa
authors.forename: Arend
authors.initials: A
authors.lastname: Heerschap
mesh_terms: D003401:Creatine / Q000378:metabolism*; D004867:Equipment Design; D006801:Humans; D007866:Leg; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D018482:Muscle, Skeletal / Q000378:metabolism*
chemical_list: D003401:Creatine