Announcements: March 3, 2008

Posted 04:52 PM, March 03, 2008, by jaruiz

Dr. Alexej Jerschow to Deliver Talk Entitled "23Na and 1H CEST MRI: Contrast in Cartilage and Intervertebral Disc": Friday, March 7th, at 10:00 AM in the Clark Center Auditorium. Associate Professor Alexej Jerschow, from the Department of Chemistry at New York University (NYU), will be visiting Stanford on March 7th to give a talk on his novel work at high field. He will be visiting the Lucas Center afterwards to see our facilities and to meet our scientists over lunch. For more information, please see his abstract below and/or contact Dr. Garry Gold.

ABSTRACT:
Glycosaminogycan (GAG) plays numerous vital functions in the human body. GAG concentration [GAG] in vivo is a sensitive biomarker indicative of both osteoarthritis (OA) and intervertebral disc (IVD) degenerative diseases. By exploiting the exchangeable protons of GAG, we demonstrate that one can directly map the localized GAG concentration in vivo using a chemical exchange saturation transfer (CEST) method. This gagCEST approach is presented on both human cartilage and animal discs. We also show the observation of the Nuclear Overhauser Effect (NOE) from macromolecules in tissue, which contributes significantly to the CEST/MT contrast mechanism in MRI and may lead to further diagnostic abilities. GAG contrast may also be enhanced by employing intermolecular multiple-quantum coherences.

Monitoring the bound sodium pool can be an important tool for assessing the onset of tissue disorders. Practical clinical 23Na MRI methods, furthermore, often do not allow one to use sufficiently small voxel sizes such that only the tissue of interest is seen, and a large signal contamination can arise from sodium in synovial fluid. Methods are presented for the clean separation between the signal from bound or ordered 23Na over that of free 23Na, which is particularly important and can greatly enhance the potential of 23Na-MRI as a diagnostic tool. 23Na MRI also offers the possibility of monitoring local anisotropic motion. 3T and 7T in vivo volumetric 23Na images are presented. Monitoring GAGs via 23Na or CEST can also be important for assessing heart valves or corneae.

References:
W. Ling, R. R. Regatte, G. Navon, A. Jerschow, Assessment of Glycosaminoglycan Concentration in Vivo by Chemical Exchange Saturation Transfer (gagCEST). Proc. Nat. Acad. Sci. USA, in press 2008, http://www.pnas.org/cgi/content/abstract/0707666105v1.

W. Ling, R. R. Regatte, M. E. Schweitzer, A. Jerschow. Characterization of Bovine Patellar Cartilage by NMR. NMR Biomed., in press 2008, http://www3.interscience.wiley.com/cgi-bin/abstract/114294661/ABSTRACT.