title: Fluorine-19 magnetic resonance angiography of the mouse.
abstract: OBJECTIVE
  To implement and characterize a fluorine-19 ((19)F) magnetic resonance imaging (MRI) technique and to test the hypothesis that the (19)F MRI signal in steady state after intravenous injection of a perfluoro-15-crown-5 ether (PCE) emulsion may be exploited for angiography in a pre-clinical in vivo animal study.
  
  
  METHODS
  In vitro at 9.4T, the detection limit of the PCE emulsion at a scan time of 10 min/slice was determined, after which the T(1) and T(2) of PCE in venous blood were measured. Permission from the local animal use committee was obtained for all animal experiments. 12 µl/g of PCE emulsion was intravenously injected in 11 mice. Gradient echo (1)H and (19)F images were obtained at identical anatomical levels. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were determined for 33 vessels in both the (19)F and (1)H images, which was followed by vessel tracking to determine the vessel conspicuity for both modalities.
  
  
  RESULTS
  In vitro, the detection limit was ∼400 µM, while the (19)F T(1) and T(2) were 1350±40 and 25±2 ms. The (19)F MR angiograms selectively visualized the vasculature (and the liver parenchyma over time) while precisely coregistering with the (1)H images. Due to the lower SNR of (19)F compared to (1)H (17±8 vs. 83±49, p<0.001), the (19)F CNR was also lower at 15±8 vs. 52±35 (p<0.001). Vessel tracking demonstrated a significantly higher vessel sharpness in the (19)F images (66±11 vs. 56±12, p = 0.002).
  
  
  CONCLUSIONS
  (19)F magnetic resonance angiography of intravenously administered perfluorocarbon emulsions is feasible for a selective and exclusive visualization of the vasculature in vivo.
authors: Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. ruud.mri@gmail.com
authors: Ruud B
authors: RB
authors: van Heeswijk
authors: Yves
authors: Y
authors: Pilloud
authors: Ulrich
authors: U
authors: Flögel
authors: Jürg
authors: J
authors: Schwitter
authors: Matthias
authors: M
authors: Stuber
mesh_terms: D000818:Animals; D043844:Crown Ethers / Q000008:administration & dosage; D005461:Fluorine; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D005466:Fluorocarbons
chemical_list: D043844:Crown Ethers; D005461:Fluorine; C089317:perfluoro-15-crown-5-ether; D005466:Fluorocarbons