Magnetization transfer effect on the creatine methyl resonance studied by CW off-resonance irradiation in human skeletal muscle on a clinical MR system.
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.
Renema
W Klaas Jan
WK
Department of Radiology, University Medical Center Nijmegen, Nijmegen, The Netherlands. k.renema@rad.umcn.nl
Klomp
Dennis W J
DW
Philippens
Mariëlle E P
ME
van den Bergh
Adrianus J
AJ
Wieringa
Bé
B
Heerschap
Arend
A
D003401:Creatine / Q000378:metabolism*; D004867:Equipment Design; D006801:Humans; D007866:Leg; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D018482:Muscle, Skeletal / Q000378:metabolism*
D003401:Creatine