Hyperpolarized lithium-6 as a sensor of nanomolar contrast agents

✍ Scribed by Ruud B. van Heeswijk; Kai Uffmann; Arnaud Comment; Fiodar Kurdzesau; Chiara Perazzolo; Cristina Cudalbu; Sami Jannin; Jacobus A. Konter; Patrick Hautle; Ben van den Brandt; Gil Navon; Jacques J. van der Klink; Rolf Gruetter

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 336 KB
• Volume: 61
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.21952

✦ Synopsis

Abstract

Lithium is widely used in psychotherapy. The ^6^Li isotope has a long intrinsic longitudinal relaxation time T~1~ on the order of minutes, making it an ideal candidate for hyperpolarization experiments. In the present study we demonstrated that lithium‐6 can be readily hyperpolarized within 30 min, while retaining a long polarization decay time on the order of a minute. We used the intrinsically long relaxation time for the detection of 500 nM contrast agent in vitro. Hyperpolarized lithium‐6 was administered to the rat and its signal retained a decay time on the order of 70 sec in vivo. Localization experiments imply that the lithium signal originated from within the brain and that it was detectable up to 5 min after administration. We conclude that the detection of submicromolar contrast agents using hyperpolarized NMR nuclei such as ^6^Li may provide a novel avenue for molecular imaging. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.