Fast volumetric spatial-spectral MR imaging of hyperpolarized 13C-labeled compounds using multiple echo 3D bSSFP.
OBJECTIVE
The goal of this work was to develop a fast 3D chemical shift imaging technique for the noninvasive measurement of hyperpolarized (13)C-labeled substrates and metabolic products at low concentration.


METHODS
Multiple echo 3D balanced steady state magnetic resonance imaging (ME-3DbSSFP) was performed in vitro on a syringe containing hyperpolarized [1,3,3-2H3; 1-(13)C]2-hydroxyethylpropionate (HEP) adjacent to a (13)C-enriched acetate phantom, and in vivo on a rat before and after intravenous injection of hyperpolarized HEP at 1.5 T. Chemical shift images of the hyperpolarized HEP were derived from the multiple echo data by Fourier transformation along the echoes on a voxel by voxel basis for each slice of the 3D data set.


RESULTS
ME-3DbSSFP imaging was able to provide chemical shift images of hyperpolarized HEP in vitro, and in a rat with isotropic 7-mm spatial resolution, 93 Hz spectral resolution and 16-s temporal resolution for a period greater than 45 s.


CONCLUSIONS
Multiple echo 3D bSSFP imaging can provide chemical shift images of hyperpolarized (13)C-labeled compounds in vivo with relatively high spatial resolution and moderate spectral resolution. The increased signal-to-noise ratio of this 3D technique will enable the detection of hyperpolarized (13)C-labeled metabolites at lower concentrations as compared to a 2D technique.
Perman
William H
WH
Department of Radiology, Saint Louis University School of Medicine, PO Box 15250, St. Louis, MO 63110-0250, USA. perman@slu.edu
Bhattacharya
Pratip
P
Leupold
Jochen
J
Lin
Alexander P
AP
Harris
Kent C
KC
Norton
Valerie A
VA
Hövener
Jan-Bernd
JB
Ross
Brian D
BD
D000465:Algorithms; D000818:Animals; D002247:Carbon Isotopes / Q000494:pharmacology*; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D007275:Injections, Intravenous; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D008956:Models, Chemical; D011422:Propionates / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D015203:Reproducibility of Results; D013997:Time Factors
C551061:2-hydroxyethylpropionate; D002247:Carbon Isotopes; D011422:Propionates; C029658:propionic acid