Abstract #1700

Quantitative Mapping of the Cl-/Na+ Concentration Ratio Using a Double Resonant Surface Coil

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.