Proton decoupled hyperpolarized magnetic resonance imaging

Abstract

A system and method for improving available signal-to-noise ratio (SNR) and speed of MR imaging of hyperpolarized substances is disclosed. The system and method include decoupling spin effects of hydrogen nuclei from non-hydrogen nuclei of interest during sampling of MR signals therefrom. Though the hydrogen nuclei of the hyperpolarized substance may not be directly bonded to the non-hydrogen nuclei of interest, resonance splitting may still impact SNR. Long range decoupling improves T2* time, and thus preserves signal strength and available SNR.

1 - 7 . (canceled) 
     
     
         8 . A method of magnetic resonance (MR) imaging comprising:
 introducing a hyperpolarized MR contrast agent into a subject of interest;   acquiring MR signals from at least the hyperpolarized contrast agent; and   during the acquisition of MR signals, saturating hydrogen nuclei to improve a signal-to-noise ratio of the acquisition.   
     
     
         9 . The method of  claim 8  wherein acquiring MR signals from at least the hyperpolarized contrast agent includes acquiring MR signals from non-hydrogen nuclei of the hyperpolarized contrast agent. 
     
     
         10 . The method of  claim 9  wherein saturating hydrogen nuclei includes saturating hydrogen nuclei which are not directly bonded to the non-hydrogen nuclei of the hyperpolarized contrast agent. 
     
     
         11 . The method of  claim 8  further comprising acquiring MR signals from at least one metabolite of the hyperpolarized contrast agent. 
     
     
         12 . The method of  claim 8  wherein saturating hydrogen nuclei includes applying a B1 excitation field. 
     
     
         13 . The method of  claim 8  wherein the saturating hydrogen nuclei is performed during a data sampling portion of the acquisition. 
     
     
         14 . The method of  claim 8  further comprising applying a long range decoupling of hydrogen nuclei and 13-C nuclei positioned at least 2 bond lengths apart to improve a signal-to-noise ratio of hyperpolarized 13-C imaging. 
     
     
         15 . A data storage medium having a set of instructions stored thereon which, when executed by a computer, causes the computer to:
 excite nuclei of a hyperpolarized substance;   decrease a resonance splitting of the hyperpolarized substance; and   sample MR signals from the nuclei for image reconstruction.   
     
     
         16 . The data storage medium of  claim 15  wherein the set of instructions further causes the computer to decrease the resonance splitting by applying a proton decoupling. 
     
     
         17 . The data storage medium of  claim 16  wherein the set of instructions further causes the computer to apply the proton decoupling to reduce JCH effects of hydrogen nuclei positioned at least two bond lengths from a 13-C nucleus. 
     
     
         18 . The data storage medium of  claim 15  wherein the hyperpolarized substance is a 13-C contrast agent. 
     
     
         19 . The data storage medium of  claim 15  wherein the set of instructions further causes the computer to excite nuclei of metabolites of the hyperpolarized substance. 
     
     
         20 . The data storage medium of  claim 19  wherein the set of instructions further causes the computer to decrease resonance splitting of the metabolites of the hyperpolarized substance.