Armin Michael Nagel1, Marc-Andr Weber2, Christian Matthies1, Julien Dinkel, Karin Jurkatt-Rott3, Frank Lehmann-Horn3, Lothar Rudi Schad4
1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany; 3Applied Physiology, University Ulm, Ulm, Germany; 4Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, University Heidelberg, Mannheim, Germany
Three different 23Na-MRI contrasts were applied and compared with regard to the information they provide about the compartments from which the 23Na signal originates. In particular, a T1-weighted, a concentration-weighted contrast, and an inversion recovery sequence, the latter of which suppresses the 23Na fluid signal were used. It was shown that the 23Na-IR sequence is well suitable to visualize an intracellular sodium accumulation, caused by provocation of the lower leg muscles in patients with hypokalemic periodic paralysis, a muscular sodium channelopathy. This is substantiated by the fact, that the total sodium concentration stays constant after provocation.