title: Simultaneous imaging of 13C metabolism and 1H structure: technical considerations and potential applications.
abstract: Real-time imaging of (13)C metabolism in vivo has been enabled by recent advances in hyperpolarization. As a result of the inherently low natural abundance of endogenous (13)C nuclei, hyperpolarized (13)C images lack structural information that could be used to aid in motion detection and anatomical registration. Motion before or during the (13)C acquisition can therefore result in artifacts and misregistration that may obscure measures of metabolism. In this work, we demonstrate a method to simultaneously image both (1)H and (13)C nuclei using a dual-nucleus spectral-spatial radiofrequency excitation and a fully coincident readout for rapid multinuclear spectroscopic imaging. With the appropriate multinuclear hardware, and the means to simultaneously excite and receive on both channels, this technique is straightforward to implement requiring little to no increase in scan time. Phantom and in vivo experiments were performed with both Cartesian and spiral trajectories to validate and illustrate the utility of simultaneous acquisitions. Motion compensation of dynamic metabolic measurements acquired during free breathing was demonstrated using motion tracking derived from (1)H data. Simultaneous multinuclear imaging provides structural (1)H and metabolic (13)C images that are correlated both spatially and temporally, and are therefore amenable to joint (1)H and (13)C analysis and correction of structure-function images.
authors: Department of Medical Physics, University of Wisconsin, Madison, WI, USA.
authors: Jeremy W
authors: JW
authors: Gordon
authors: Sean B
authors: SB
authors: Fain
authors: David J
authors: DJ
authors: Niles
authors: Kai D
authors: KD
authors: Ludwig
authors: Kevin M
authors: KM
authors: Johnson
authors: Eric T
authors: ET
authors: Peterson
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000493:pharmacokinetics*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007668:Kidney / Q000033:anatomy & histology / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D008813:Mice, Inbred ICR; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D011522:Protons; D019289:Pyruvic Acid; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002247:Carbon Isotopes; D011522:Protons; D019344:Lactic Acid; D019289:Pyruvic Acid
keywords: dynamic nuclear polarization; hyperpolarized; pyruvate; simultaneous; spectral-spatial excitation; spiral