Hyperpolarized Carbon-13 Metabolic Imaging Methods

Hyperpolarized carbon-13 magnetic resonance imaging (MRI) is a relatively new type of imaging study which offers novel metabolic information and contrast, unlike conventional MRI which provides primarily anatomical information.  It is particularly promising for cancer imaging applications, such as disease staging, surgical planning, and monitoring response to therapy, because it highlights functional changes in cellular activity.  UCSF has been a leader in this field, performing the first in vivo human studies in prostate cancer patients.  (Featured in a news segment from KTVU)

Hyperpolarized carbon-13 MRI requires specialized methods because, unlike conventional MRI, the signal decays rapidly and is unrecoverable.  The Larson Lab is working to develop new rapid and efficient hyperpolarized MRI methods, including dynamic metabolic imaging for localized perfusion and rate information, new contrast generation methods to distinguish metabolites in different compartments (ie blood vessels, intracellular, extracellular), and development of specialized techniques for simultaneous imaging of multiple carbon-13 agents.

Dynamic Imaging

Link: Movies and additional information

Peder E. Z. Larson, Robert Bok, A. B. Kerr, M. Lustig, S. Hu, A. P. Chen, S. J. Nelson, John M. Pauly, J. Kurhanewicz, and D. B. Vigneron. Investigation of tumor hyperpolarized [1-13C]-pyruvate dynamics using time-resolved multiband RF excitation echo-planar MRSI. Magn Reson Med, 63(3):582-591, March 2010.

Peder E. Z. Larson, Simon Hu, Michael Lustig, Adam B. Kerr, Sarah J. Nelson, John Kurhanewicz, John M. Pauly, and Daniel B. Vigneron. Fast dynamic 3D MRSI with compressed sensing and multiband excitation pulses for hyperpolarized 13C. Magn Reson Med. 65(3): 610-619, March 2011.

Diffusion/Perfusion Imaging

P. E. Z. Larson, R. E. Hurd, A. B. Kerr, R. Bok, J. Kurhanewicz, and D. B. Vigneron. Stimulated-echo contrast with hyperpolarized [1-13C]-pyruvate. In Proceedings of the 18th Annual Meeting of ISMRM, page 375, Stockholm, 2010.

Semi-solid Tissue Imaging with Ultrashort Echo Time (UTE) MRI

In conventional MRI techniques, tissues with rapid transverse relaxation times (< 2 ms) are undetectable and thus appear invisible.  These tissues are solid or semi-solid, and include cortical bone, tendons, and other connective tissues, as well as certain components of cartilage, ligaments, and myelin.  Ultrashort echo time (UTE) MRI uses specialized RF pulses and acquisition schemes to detect signal from these tissues.  This provides positive contrast that may be clinically valuable when observing these types of tissues.

The Larson Lab is working on techniques to improve UTE MRI.  These include novel contrast generation through RF pulses and multiple echo times, accelerated acquisitions, and improved image reconstructions.

Peder E. Z. Larson, Paul T. Gurney, Krishna Nayak, Garry E. Gold, John M. Pauly, and Dwight G. Nishimura. Designing long-T2 suppression pulses for ultrashort echo time imaging. Magn Reson Med, 56(1):94-103, July 2006.

Krug R, Larson PE, Wang C, Burghardt AJ, Kelley DA, Link TM, Zhang X, Vigneron DB, Majumdar S. Ultrashort echo time MRI of cortical bone at 7 tesla field strength: A feasibility study. J Magn Reson Imaging. 2011 Jul 18.