Regensburg 2010 – scientific programme
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ST: Fachverband Strahlen- und Medizinphysik
ST 10: Basic and Applied Medical Physics (Poster Session)
ST 10.1: Poster
Wednesday, March 24, 2010, 16:00–17:00, H41
MRI Thermometry Based on Encapsulated Hyperpolarized Xenon — •Franz Schilling1,2,3,5, Leif Schröder1,2,4, Kanna Palanniappan1, Sina Zapf3, David E. Wemmer1,2, and Alexander Pines1,2 — 1University of California, QB3, Berkeley — 2Lawrence Berkeley National Laboratory — 3University of Würzburg, Department of Experimental Physics 5 — 4Leibniz Institute for Molecular Pharmacology (FMP), Berlin — 5Technical University Munich, Department of Chemistry
Noninvasive, accurate and spatially resolved temperature measurement in the human body is a desired technology for many biomedical applications, including hyperthermic treatment of cancer and detection of vulnerable atherosclerotic plaques. A new MRI thermometry approach using encapsulated hyperpolarized xenon is demonstrated in this work. It is based on the temperature dependent chemical shift of hyperpolarized xenon in a cryptophane-A cage. This shift is linear and was determined to be 0.29 ppm/K with respect to the peak of free xenon in dissolved in water. This value is 30 times higher than the shift of the proton resonance frequency that is currently used for MRI thermometry. Direct MR temperature imaging with caged xenon was shown with a chemical shift imaging (CSI) sequence for the spin 1/2 nucleus 129Xe and homogeneous temperature maps of a phantom could be collected with an accuracy of 0.1 K at a sensor concentration of 150 µM. Another setup allowed visualization of a temperature gradient with a span of only 2 K. MRI thermometry based on hyperpolarized encapsulated xenon improves the accuracy of available MRI thermometry methods.