Abstract #2462

Sub-Micromolar Concentrations of Contrast Agent Have a Quantifiable Influence on the Hyperpolarized Lithium-6 Relaxation Time in Vivo

Ruud Bernardus van Heeswijk¹, Fiodar Kurdzesau^2,3, Cristina Cudalbu¹, Arnaud Comment^1,2, Jacques J. van der Klink², Gil Navon⁴, Rolf Gruetter^1,5

¹Center for BioMedical Imaging (CIBM), Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, VD, Switzerland; ²Laboratory for Physics of Nanostructured Materials, Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, VD, Switzerland; ³Paul Scherrer Institute, Villigen, Switzerland; ⁴School of Chemistry, Tel Aviv University, Tel-Aviv, Israel; ⁵Departments of Radiology, Universities of Lausanne and Geneva, Switzerland

Lithium-6 has recently been demonstrated to have longitudinal decay times on the order of minutes and to be readily hyperpolarizable by dynamic nuclear polarization (DNP). It was also shown to be quite sensitive to the negatively charged contrast agent Gd-DOTP. The aim of this study was to demonstrate that these principles can be combined to quantitatively detect very low concentrations of contrast agent: the longer the relaxation time, the more sensitive it becomes to the contrast agent.