Renema WKJ, Klomp DWJ, Philippens MEP, van den Bergh AJ, Wieringa B, Heerschap A. Magnetization transfer effect on the creatine methyl resonance studied by CW off-resonance irradiation in human skeletal muscle on a clinical MR system.
Magn Reson Med 2003;
50:468-73. [PMID:
12939753 DOI:
10.1002/mrm.10564]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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.
Collapse