In vivo hyperpolarized 13 C MR spectroscopic imaging with 1 H decoupling

Application of 13 C MRS in vivo on whole body MR system has been limited due to the low static field (and consequent low signal to noise ratio—SNR) of these scanners; thus there have been few reports of 1 H decoupled 13 C MRS in vivo using a clinical MR platform. The recent development of techniques to retain highly polarized spins in solution following DNP in a solid matrix has provided a mechanism to use endogenous pre-polarized 13 C labeled substrates to study real time cellular metabolism in vivo with high SNR. In a recent in vivo hyperpolarized metabolic imaging study using 13 C pyruvate, it has been demonstrated that the line shape (signal decay) of the resonances observed are greatly affected by JCH coupling in addition to inhomogeneous broadening. This study demonstrates the feasibility of improving hyperpolarized 13 C metabolic imaging in vivo by incorporating 1 H decoupling on a clinical whole body 3 T MR scanner. No reduction of T1 of a prepolarized 13 C substrate ([1- 13 C] lactate) in solution was observed when 1 H decoupling was applied with WALTZ16 sequence. Narrower linewidth for the [1- 13 C] lactate resonance was observed in hyperpolarized 13 C MRSI data in vivo with 1 H decoupling.