title: Proton magnetic resonance imaging with para-hydrogen induced polarization.
abstract: A major challenge in imaging is the detection of small amounts of molecules of interest. In the case of magnetic resonance imaging (MRI) their signals are typically concealed by the large background signal of e.g. the body. This problem can be tackled by hyperpolarization which increases the NMR signals up to several orders of magnitude. However, this strategy is limited for (1)H, the most widely used nucleus in NMR and MRI, because the enormous number of protons in the body screens the small amount of hyperpolarized ones. Here, we describe a method giving rise to high (1)H MRI contrast for hyperpolarized molecules against a large background signal. The contrast is based on the J-coupling induced rephasing of the NMR signal of molecules hyperpolarized via PHIP and it can easily be implemented in common pulse sequences. We discuss several scenarios with different or equal dephasing times T(2)* for the hyperpolarized and thermally polarized compounds and verify our approach by experiments. This method may open up unprecedented opportunities to use the standard MRI nucleus (1)H for e.g. metabolic imaging in the future.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Dechent
authors.forename: Lisandro
authors.initials: L
authors.lastname: Buljubasich
authors.forename: Laura M
authors.initials: LM
authors.lastname: Schreiber
authors.forename: Hans W
authors.initials: HW
authors.lastname: Spiess
authors.forename: Kerstin
authors.initials: K
authors.lastname: Münnemann
mesh_terms: D003287:Contrast Media / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D011522:Protons
chemical_list: D003287:Contrast Media; D011522:Protons; D006859:Hydrogen