Sodium Magnetic Resonance Imaging: From Research to Clinical Use

Abstract

Many exciting new variations of magnetic resonance imaging (MRI) have been tested in magnetic resonance research, but only a few have found their way to clinical use. Sodium (23Na) MRI is one of those techniques that at first glance seemed to be very promising. Sodium MRI has the potential to extend MRI beyond anatomic imaging by providing information on physiology and cellular metabolism. Signal strength is related to disease-specific changes in the tissue. This type of disease-specific contrast can compensate for the much lower signal/noise ratio (SNR) of these techniques. The contrast between ischemic [ 1 Constantinides C.D. Kraitchman D.L. O’Brien K.O. Boada F.E. Gillen J. Bottomley P.A. Noninvasive quantification of total sodium concentrations in acute reperfused myocardial infarction using 23Na MRI. Magn Reson Med. 2001; 46: 1144-1151 Crossref PubMed Scopus (62) Google Scholar ] and healthy cardiac tissue and between benign tissue and malignant tumors [ 2 Ouwerkerk R. Bleich K.B. Gillen J.S. Pomper M.G. Bottomley P.A. Tissue sodium concentration in human brain tumors as measured with 23Na MR imaging. Radiology. 2003; 227: 529-537 Crossref PubMed Scopus (226) Google Scholar ] is based on significant changes in tissue sodium concentration (TSC). For stroke in humans, an increase in TSC of 50% was recorded [ 3 Thulborn K.R. Davis D. Snyder J. Yonas H. Kassam A. Sodium MR imaging of acute and subacute stroke for assessment of tissue viability. Neuroimaging Clin North Am. 2005; 15: 639-653 Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar ].