Renema W Klaas Jan, Klomp Dennis W J, Philippens Mariëlle E P, van den Bergh Adrianus J, Wieringa Bé, Heerschap Arend
Department of Radiology, University Medical Center Nijmegen, Nijmegen, The Netherlands.
Magn Reson Med. 2003 Sep;50(3):468-73. doi: 10.1002/mrm.10564.
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.
