Abstract #0059

Imaging Brain PH Using Hyperpolarized 13C-Labeled Bicarbonate

Ferdia Aidan Gallagher^1,2, Mikko I. Kettunen^2,3, De-en Hu^2,3, Lorna B. Jarvis⁴, Rebekah L. McLaughlin^2,3, Tim H. Witney^2,3, Sam E. Day^2,3, Jan H. Ardenkjaer-Larsen⁵, Ken G. Smith⁴, Kevin M. Brindle^2,3

¹Radiology, University of Cambridge, Cambridge, UK; ²CRUK Cambridge Research Institute, Cambridge, UK; ³Biochemistry, University of Cambridge, Cambridge, UK; ⁴Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK; ⁵GE Healthcare, Amersham, UK

Few imaging biomarkers can cross an intact blood-brain barrier. We show here that hyperpolarized ¹³C-labeled carbon dioxide can be detected within normal mouse brain following the injection of hyperpolarized ¹³C-labeled bicarbonate. The spatial distribution of the two molecules can also be imaged and the calculated brain pH was shown to be lower than the surrounding tissues, in keeping with previous invasive studies. This method therefore offers the possibility of a new cerebral imaging technique which could be applied to imaging brain function and pathology.