In vitro demonstration using 19F magnetic resonance to augment molecular imaging with paramagnetic perfluorocarbon nanoparticles at 1.5 Tesla.
OBJECTIVE
This study explored the use of F spectroscopy and imaging with targeted perfluorocarbon nanoparticles for the simultaneous identification of multiple bio-signatures at 1.5 T.


METHODS
Two nanoparticle emulsions with perfluoro-15-crown-5-ether (CE) or perfluorooctylbromide (PFOB) cores were targeted in vitro to fibrin clot phantoms (n=12) in 4 progressive ratios using biotin-avidin interactions. The CE nanoparticles incorporated gadolinium. Fluorine images were acquired using steady-state gradient-echo techniques; spectra using volume-selective and nonselective sampling.


RESULTS
On conventional T1-weighted imaging, clots with CE nanoparticles enhanced as expected, with intensity decreasing monotonically with CE concentration. All clots were visualized using wide bandwidth fluorine imaging, while restricted bandwidth excitation permitted independent imaging of CE or PFOB nanoparticles. Furthermore, F imaging and spectroscopy allowed visual and quantitative confirmation of relative perfluorocarbon nanoparticle distributions.


CONCLUSIONS
F MRI/S molecular imaging of perfluorocarbon nanoparticles in vitro suggests that noninvasive phenotypic characterization of pathologic bio-signatures is feasible at clinical field strengths.
Caruthers
Shelton D
SD
Division of Cardiology, Washington University Medical School, St. Louis, Missouri 63110, USA. SCaruthers@cmrl.wustl.edu
Neubauer
Anne M
AM
Hockett
Frank D
FD
Lamerichs
Rolf
R
Winter
Patrick M
PM
Scott
Michael J
MJ
Gaffney
Patrick J
PJ
Wickline
Samuel A
SA
Lanza
Gregory M
GM
D000818:Animals; D004285:Dogs; D004655:Emulsions; D005337:Fibrin / Q000378:metabolism*; D005461:Fluorine; D019786:Gadolinium DTPA; D006845:Hydrocarbons, Fluorinated; D066298:In Vitro Techniques; D049329:Nanostructures; D019906:Nuclear Magnetic Resonance, Biomolecular; D019047:Phantoms, Imaging; D013927:Thrombosis / Q000175:diagnosis*
D004655:Emulsions; D006845:Hydrocarbons, Fluorinated; D005461:Fluorine; D005337:Fibrin; D019786:Gadolinium DTPA