title: Application of double spin echo spiral chemical shift imaging to rapid metabolic mapping of hyperpolarized [1-¹³C]-pyruvate.
abstract: Undersampled spiral CSI (spCSI) using a free induction decay (FID) acquisition allows sub-second metabolic imaging of hyperpolarized ¹³C. Phase correction of the FID acquisition can be difficult, especially with contributions from aliased out-of-phase peaks. This work extends the spCSI sequence by incorporating double spin echo radiofrequency (RF) pulses to eliminate the need for phase correction and obtain high quality spectra in magnitude mode. The sequence also provides an added benefit of attenuating signal from flowing spins, which can otherwise contaminate signal in the organ of interest. The refocusing pulses can potentially lead to a loss of hyperpolarized magnetization in dynamic imaging due to flow of spins through the fringe field of the RF coil, where the refocusing pulses fail to provide complete refocusing. Care must be taken for dynamic imaging to ensure that the spins remain within the B₁-homogeneous sensitive volume of the RF coil.
authors.affiliation: SRI International, Neuroscience Program, Menlo Park, CA 94025, USA. sjosan@stanford.edu
authors.forename: Sonal
authors.initials: S
authors.lastname: Josan
authors.forename: Yi-Fen
authors.initials: YF
authors.lastname: Yen
authors.forename: Ralph
authors.initials: R
authors.lastname: Hurd
authors.forename: Adolf
authors.initials: A
authors.lastname: Pfefferbaum
authors.forename: Daniel
authors.initials: D
authors.lastname: Spielman
authors.forename: Dirk
authors.initials: D
authors.lastname: Mayer
mesh_terms: D000409:Alanine / Q000378:metabolism; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000033:anatomy & histology; D019344:Lactic Acid / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D019289:Pyruvic Acid / Q000737:chemistry*; D051381:Rats; D012984:Software; D014316:Tritium
chemical_list: D001639:Bicarbonates; D002250:Carbon Radioisotopes; D014316:Tritium; D019344:Lactic Acid; D019289:Pyruvic Acid; D000409:Alanine