title: Accelerating hyperpolarized metabolic imaging of the heart by exploiting spatiotemporal correlations.
abstract: Hyperpolarized (13)C-labeled pyruvate is a promising tool to investigate cardiac metabolism. It has been shown that changes in substrate metabolism occur following the induction of ischemia. To investigate the metabolic changes that are confined to spatial regions, high spatiotemporal resolution is required. The present work exploits both spatial and temporal correlations using k-t principal component analysis (PCA) to undersample the spatiotemporal domain, thereby speeding up data acquisition. A numerical model was implemented to investigate optimal acquisition and reconstruction parameters for pyruvate, lactate and bicarbonate maps of the heart. Subsequently, prospectively undersampled in vivo data on rat hearts were acquired using a combination of spectral-spatial signal excitation and a variable-density single-shot echo planar readout. Using five-fold k-t PCA, a spatial resolution of 1 × 1 mm(2) at a temporal resolution of 3 s was achieved.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
authors.forename: Kilian
authors.initials: K
authors.lastname: Weiss
authors.forename: Andreas
authors.initials: A
authors.lastname: Sigfridsson
authors.forename: Lukas
authors.initials: L
authors.lastname: Wissmann
authors.forename: Julia
authors.initials: J
authors.lastname: Busch
authors.forename: Michael
authors.initials: M
authors.lastname: Batel
authors.forename: Marcin
authors.initials: M
authors.lastname: Krajewski
authors.forename: Matthias
authors.initials: M
authors.lastname: Ernst
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kozerke
mesh_terms: D000818:Animals; D003198:Computer Simulation; D005260:Female; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055432:Metabolomics / Q000379:methods*; D009206:Myocardium / Q000378:metabolism*; D025341:Principal Component Analysis; D051381:Rats; D017208:Rats, Wistar; D012815:Signal Processing, Computer-Assisted; D062211:Spatio-Temporal Analysis; D013997:Time Factors
keywords: cardiac metabolism; dynamic nuclear polarization; k-t principal component analysis; k-t undersampling; spectral-spatial excitation