Application of subsecond spiral chemical shift imaging to real-time multislice metabolic imaging of the rat in vivo after injection of hyperpolarized 13C1-pyruvate.
Dynamic nuclear polarization can create hyperpolarized compounds with MR signal-to-noise ratio enhancements on the order of 10,000-fold. Both exogenous and normally occurring endogenous compounds can be polarized, and their initial concentration and downstream metabolic products can be assessed using MR spectroscopy. Given the transient nature of the hyperpolarized signal enhancement, fast imaging techniques are a critical requirement for real-time metabolic imaging. We report on the development of an ultrafast, multislice, spiral chemical shift imaging sequence, with subsecond acquisition time, achieved on a clinical MR scanner. The technique was used for dynamic metabolic imaging in rats, with measurement of time-resolved spatial distributions of hyperpolarized (13)C(1)-pyruvate and metabolic products (13)C(1)-lactate and (13)C(1)-alanine, with a temporal resolution of as fast as 1 s. Metabolic imaging revealed different signal time courses in liver from kidney. These results demonstrate the feasibility of real-time, hyperpolarized metabolic imaging and highlight its potential in assessing organ-specific kinetic parameters.
Mayer
Dirk
D
Department of Radiology, Stanford University, Richard M Lucas Center for Imaging, Stanford, California 94305-5488, USA. dirk.mayer@stanford.edu
Yen
Yi-Fen
YF
Tropp
James
J
Pfefferbaum
Adolf
A
Hurd
Ralph E
RE
Spielman
Daniel M
DM
D000465:Algorithms; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D002247:Carbon Isotopes / Q000493:pharmacokinetics; D003199:Computer Systems; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D019289:Pyruvic Acid / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D002247:Carbon Isotopes; D019289:Pyruvic Acid