title: DNP in MRI: an in-bore approach at 1.5 T.
abstract: We have used liquid state ("Overhauser") Dynamic Nuclear Polarization (DNP) to significantly enhance the signal to noise ratio (SNR) of Magnetic Resonance Imaging (MRI). For the first time this was achieved by hyperpolarizing directly in the MRI-scanner field of 1.5 T in continuous flow mode and immediately delivering the hyperpolarized substance to the imaging site to ensure maximum contrast between hyperpolarized sample and sample at thermal polarization. We achieve a maximum absolute signal enhancement factor of 98; while the hyperpolarized sample is transported at a flow rate of up to 30 ml/h yielding an average flow speed up to 470 mm/s over a distance of approximately 80 mm. A spatial imaging resolution of 100 μm with a signal to noise ratio of 25 was achieved on the flowing sample. Application to MRI contrast enhancement or microfluidic imaging can be envisaged immediately.
authors.affiliation: Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany. krummenacker@prisner.de
authors.forename: Jan G
authors.initials: JG
authors.lastname: Krummenacker
authors.forename: Vasyl P
authors.initials: VP
authors.lastname: Denysenkov
authors.forename: Maxim
authors.initials: M
authors.lastname: Terekhov
authors.forename: Laura M
authors.initials: LM
authors.lastname: Schreiber
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Prisner
mesh_terms: D003300:Copper; D003497:Cyclic N-Oxides / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D013113:Spin Labels; D003300:Copper; C001803:tempol