title: Increase in SNR for 31P MR spectroscopy by combining polarization transfer with a direct detection sequence.
abstract: The sensitivity of (31)P MRS can be increased using higher magnetic fields, but also by using (1)H to (31)P polarization transfer techniques where the sensitivity is determined by the polarization of the proton spins and thus the signal-to-noise per unit time is unaffected by the slow T(1) relaxation properties of the (31)P spins. This implies that (31)P spins can be manipulated during the T(1) relaxation of the (1)H spins without affecting the signal-to-noise of the (1)H to (31)P polarization transferred spins. It is shown here that by combining (1)H to (31)P polarization transfer with a direct (31)P detection sequence in one repetition time, one can gain more signal-to-noise per unit of time as compared to a polarization transfer sequence alone. Proof of principle was demonstrated by phantom measurements and additionally the method was applied to the human calf muscle and to the human breast in vivo at 7 T.
authors.affiliation: Department of Radiology, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands. w.j.m.vanderkemp@umcutrecht.nl
authors.forename: W J M
authors.initials: WJ
authors.lastname: van der Kemp
authors.forename: V O
authors.initials: VO
authors.lastname: Boer
authors.forename: P R
authors.initials: PR
authors.lastname: Luijten
authors.forename: J P
authors.initials: JP
authors.lastname: Wijnen
authors.forename: D W J
authors.initials: DW
authors.lastname: Klomp
mesh_terms: D000465:Algorithms; D001940:Breast / Q000378:metabolism*; D004952:Esters; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010759:Phosphorus Isotopes / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio
chemical_list: D004952:Esters; D010759:Phosphorus Isotopes