title: Hyperpolarized choline as an MR imaging molecular probe: feasibility of in vivo imaging in a rat model.
abstract: OBJECTIVE
  To assess the feasibility of choline MRI using a new choline molecular probe for dynamic nuclear polarization (DNP) hyperpolarized MRI.
  
  
  METHODS
  Male Sprague-Dawley rats with an average weight of 400 ± 20 g (n = 5), were anesthetized and injection tubing was placed in the tail vein. [1,1,2,2-D4 , 1-(13) C]choline chloride (CMP1) was hyperpolarized by DNP and injected into rats at doses ranging from 12.6 to 50.0 mg/kg. Coronal projection (13) C imaging was performed on a 3 Tesla clinical MRI scanner (bore size 60 cm) using a variable flip angle gradient echo sequence. Images were acquired 15 to 45 s after the start of bolus injection. Signal intensities in regions of interest were determined at each time point and compared.
  
  
  RESULTS
  (13) C MRI images of hyperpolarized CMP1 at a 50 mg/kg dose showed time-dependent organ distribution patterns. At 15 s, high intensities were observed in the inferior vena cava, heart, aorta, and kidneys. At 30 s, most of the signal intensity was localized to the kidneys. These distribution patterns were reproduced using 12.6 and 25 mg/kg doses. At 45 s, only signal in the kidneys was detected.
  
  
  CONCLUSIONS
  Hyperpolarized choline imaging with MRI is feasible using a stable-isotope labeled choline analog (CMP1). Nonradioactive imaging of choline accumulation may provide a new investigatory dimension for kidney physiology. J. Magn. Reson. Imaging 2015;41:917-923. © 2014 Wiley Periodicals, Inc.
authors.affiliation: Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Lanette J
authors.initials: LJ
authors.lastname: Friesen-Waldner
authors.forename: Trevor P
authors.initials: TP
authors.lastname: Wade
authors.forename: Kundan
authors.initials: K
authors.lastname: Thind
authors.forename: Albert P
authors.initials: AP
authors.lastname: Chen
authors.forename: J Moshe
authors.initials: JM
authors.lastname: Gomori
authors.forename: Jacob
authors.initials: J
authors.lastname: Sosna
authors.forename: Charles A
authors.initials: CA
authors.lastname: McKenzie
authors.forename: Rachel
authors.initials: R
authors.lastname: Katz-Brull
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000493:pharmacokinetics*; D002794:Choline / Q000493:pharmacokinetics*; D005240:Feasibility Studies; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000493:pharmacokinetics; D009928:Organ Specificity; D019275:Radiopharmaceuticals; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D002247:Carbon Isotopes; D015335:Molecular Probes; D019275:Radiopharmaceuticals; D002794:Choline
keywords: choline; magnetic resonance imaging; metabolism