Sebastian Baier1, Stefan Kirsch1, Friedrich Wetterling1, Laurent Tritschler2, Patrick Heiler1, Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Department of Neurology, Heidelberg University, Mannheim, Germany
Here we present a method which enables non-invasive determination of the Cl-/Na+ concentration ratio by means of MRI. The method employs a double resonant 35Cl-23Na surface coil which uses the same tunable loop element for measuring the 35Cl and 23Na signal. Since our sample dimensions are much smaller than λ/10, the 35Cl and the 23Na image exhibit approximately the same B1 profile. Using a reference with known Cl-/Na+ concentration enables calculation of a concentration ratio map by simply dividing the 35Cl image by the 23Na image.