title: Characterization of perfluorocarbon relaxation times and their influence on the optimization of fluorine-19 MRI at 3 tesla.
abstract: To characterize and optimize19F MRI for different perfluorocarbons (PFCs) at 3T and quantify the loss of acquisition efficiency as a function of different temperature and cellular conditions.
  
  
  
  The T1and T2relaxation times of the commonly used PFCs perfluoropolyether (PFPE), perfluoro-15-crown-5-ether (PFCE), and perfluorooctyl bromide (PFOB) were measured in phantoms and in several different conditions (cell types, presence of fixation agent, and temperatures). These relaxation times were used to optimize pulse sequences through numerical simulations. The acquisition efficiency in each cellular condition was then determined as the ratio of the signal after optimization with the reference relaxation times and after optimization with its proper relaxation times. Finally, PFC detection limits were determined.
  
  
  
  The loss of acquisition efficiency due to parameter settings optimized for the wrong temperature and cellular condition was limited to 13%. The detection limits of all PFCs were lower at 24 °C than at 37 °C and varied from 11.8 ± 3.0 mM for PFCE at 24 °C to 379.9 ± 51.8 mM for PFOB at 37 °C.
  
  
  
  Optimizing19F pulse sequences with a known phantom only leads to moderate loss in acquisition efficiency in cellular conditions that might be encountered in in vivo and in vitro experiments. Magn Reson Med 77:2263-2271, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
authors.forename: Roberto
authors.initials: R
authors.lastname: Colotti
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
authors.forename: Jessica A M
authors.initials: JAM
authors.lastname: Bastiaansen
authors.affiliation: Ludwig Center for Cancer Research, University of Lausanne (UNIL), Epalinges, Switzerland.
authors.forename: Anne
authors.initials: A
authors.lastname: Wilson
authors.affiliation: Department of Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Flögel
authors.affiliation: Division of Cardiology and Cardiac MR Center, Department of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Gonzales
authors.affiliation: Division of Cardiology and Cardiac MR Center, Department of Internal Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland.
authors.forename: Juerg
authors.initials: J
authors.lastname: Schwitter
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.|Center for Biomedical Imaging (CIBM), Lausanne and Geneva, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
authors.forename: Ruud B
authors.initials: RB
authors.lastname: van Heeswijk
mesh_terms: D043844:Crown Ethers / Q000737:chemistry; D004987:Ethers / Q000737:chemistry; D005461:Fluorine / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry*; D006842:Hydrocarbons, Brominated; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D043844:Crown Ethers; D004987:Ethers; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; C089317:perfluoro-15-crown-5-ether; C078113:perfluoropolyether; D005461:Fluorine; C003072:perflubron
keywords: balanced steady-state free precession; detection limit; fluorine MRI; perfluorocarbon; pulse sequence optimization; turbo spin echo