title: Optimization of localized 19F magnetic resonance spectroscopy for the detection of fluorinated drugs in the human liver.
abstract: Fluorine MR spectroscopy ((19)F MRS) is an indispensable tool for assessing the pharmacokinetics of fluorinated drugs. Since the metabolism of 5-fluorouracil (5FU), a frequently used cytotoxic drug, is expected to be different in normal liver and in tumor tissue, spatial localization is required for detection by MRS. In this study, three independent signal-to-noise ratio (SNR) optimizations were combined to enable chemical shift imaging (CSI) as a localization method in the detection of 5FU and its metabolites in tumor tissue. First, the hardware was optimized by using circularly polarized coils together with integrated preamplifiers. Second, the optimal pulse angle (Ernst angle) was determined on the basis of T(1) relaxation time measurements of 5FU. Finally, averaging of CSI phase-encoding steps was optimized by using the applied Hamming filter as a weighting function. The combination of these three methods enables the in vivo detection of 5FU and alpha-fluoro-beta-alanine (FBAL) by (19)F MRS, localized in three dimensions in tumor and liver tissue at a time resolution of 4 min at 1.5 Tesla.
authors.affiliation: Department of Radiology, University Medical Center Nijmegen, Nijmegen, The Netherlands. d.klomp@rad.umcn.nl
authors.forename: Dennis W J
authors.initials: DW
authors.lastname: Klomp
authors.forename: Hanneke W M
authors.initials: HW
authors.lastname: Van Laarhoven
authors.forename: Arno P M
authors.initials: AP
authors.lastname: Kentgens
authors.forename: Arend
authors.initials: A
authors.lastname: Heerschap
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000493:pharmacokinetics*; D005462:Fluorine Radioisotopes; D005472:Fluorouracil / Q000493:pharmacokinetics*; D006801:Humans; D008099:Liver / Q000737:chemistry*; D008113:Liver Neoplasms / Q000378:metabolism* / Q000556:secondary; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019047:Phantoms, Imaging; D015091:beta-Alanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D000964:Antimetabolites, Antineoplastic; D005462:Fluorine Radioisotopes; D015091:beta-Alanine; C032348:alpha-fluoro-beta-alanine; D005472:Fluorouracil