Session ThOE. There are 3 abstracts in this session.

Session: MR SPECTROSCOPY in-vivo and ex-vivo, time: 10:45 - 11:10 am

Fast spectroscopic imaging at 3T and 7T

Jullie Pan1; Victor Yushmanov1; Chan Moon1, 2; Claud Schirda2; Hoby Hetherington1
1University of Pittsburgh, Pittsburgh, PA; 2UPMC, Pittsburgh, PA

In spectroscopic imaging, conventional encoding requires a separate TR for each k-space point, which for moderate or high resolution acquisitions can require more than 15min for a single slice study. With the high SNR now available with UHF systems, encoding methods that are more efficient for spatial encoding are thus advantageous. We discuss and demonstrate implementation of the rosette trajectory for spectroscopic imaging which exhibits flexibility in trajectory design, has excellent efficiency in encoding and reduced gradient demands. Implemented with moderate spin echo and j-refocused sequences, the rosette data demonstrate the characteristic gray matter dependence of creatine and glutamate. The rosette has also been tested in tumor and epilepsy patients to show sensitivity to pathology.

Session: MR SPECTROSCOPY in-vivo and ex-vivo, time: 11:35 - 12:00

Towards in vivo whole-brain neurochemical fingerprinting at ultra-high field

Wolfgang Bogner
Medical University Vienna, Vienna, Austria

Conventional spin-echo MR spectroscopic imaging (MRSI) techniques cannot fully exploit the benefits that ultra-high field MR scanners (e.g., 7Tesla) offer for in vivo MRSI of the brain. Direct echo-less Free induction decay (FID)- MRSI techniques have emerged as a superior approach that overcomes multiple technical challenges that MRSI has to face beyond clinical field strength (>3 Tesla). The resulting boost in spectral quality can be efficiently translated into much higher spatial resolution, detection of a much more comprehensive neurochemical profile, and that at significantly reduced scan times. This has major implications for the clinical application of in vivo whole-brain MRSI at ultra-high field.

Session: MR SPECTROSCOPY in-vivo and ex-vivo, time: 12:00 - 12:15 pm

Optimization of Proton MRS of Deoxymyoglobin in Human Skeletal Muscle at 3T: a tool for measuring Intracellular O2 availability

Rajakumar Nagarajan1; Saadallah Ramadan2; Stephen Decker3; Gwenael Layec3
1Human Magnetic Resonance Center, IALS, UMass, Amherst, MA; 2School of Health Sciences, University of Newcastle, Newcastle, Australia; 3Kinesiology and IALS, UMass, Amherst, MA

Proton magnetic resonance spectroscopy (MRS) of deoxymyoglobin (deoxy-Mb) can monitor non-invasively the oxygenation state of human skeletal muscle. The detection of deoxy-Mb is challenging due to its short relaxation time and low concentration. Therefore, the major goal of this study was to optimize the detection of the n–δ proton of the proximal histidine F8 of myoglobin in the deoxygenated state in the skeletal muscle on a 3T MRI/MRS scanner by optimizing several sequence parameters (Flip angle, repetition time, carrier frequency, bandwidth) using non-localized MRS technique.