Noninvasive measurements of transmural myocardial metabolites using 3-D (31)P NMR spectroscopy.
A completely noninvasive three-dimensional (3-D) static magnetic field magnitude spatially localized (31)P spectroscopy technique has been developed and applied to study the in vivo canine myocardium at 9.4 T. The technique incorporates both Fourier series windows and selective Fourier transform methods utilizing all three orthogonal gradients for 3-D phase encoding. The number of data acquisitions for each phase-encoding step was weighted according to the Fourier coefficients to define cylindrical voxels. Spatially localized (31)P spectra can be generated for voxels of desired location within the field of view as a postprocessing step. The quality of localization was first demonstrated by using a three-compartment phantom. The technique was then applied to in vivo canine models and yielded (31)P cardiac spectra with an excellent signal-to-noise ratio. The in vivo validation experiments, using an implanted 2-phosphoenolpyruvate-containing marker, demonstrated that the technique is capable of measuring at least two transmural layers of left ventricular myocardium representing the subepicardium and subendocardium.
Cho
Y K
YK
Center for Magnetic Resonance Research and Departments of Medicine and Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Merkle
H
H
Zhang
J
J
Tsekos
N V
NV
Bache
R J
RJ
Ugurbil
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D000465:Algorithms; D000818:Animals; D004285:Dogs; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000378:metabolism; D017379:Hypertrophy, Left Ventricular / Q000378:metabolism / Q000473:pathology; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008953:Models, Anatomic; D009206:Myocardium / Q000378:metabolism*; D019047:Phantoms, Imaging; D010725:Phosphocreatine / Q000378:metabolism; D015203:Reproducibility of Results
D010725:Phosphocreatine; D000255:Adenosine Triphosphate