title: 3D radial projection technique with ultrashort echo times for sodium MRI: clinical applications in human brain and skeletal muscle.
abstract: (23)Na MRI has the potential to noninvasively detect sodium (Na) content changes in vivo. The goal of this study was to implement (23)Na MRI in a clinical setting for neurooncological and muscular imaging. Due to the biexponential T(2) decay of the tissue Na signal with a short component, which ranges between 0.5-8 ms, the measurement of total Na content requires imaging techniques with echo times (TEs) below 0.5 ms. A 3D radial pulse sequence with a TE of 0.2 ms at a spatial resolution of 4 x 4 x 4 mm(3) was developed that allows the acquisition and presentation of Na images on the scanner. This sequence was evaluated in patients with low- and high-grade gliomas, and higher (23)Na MR signals corresponding to an increased Na content were found in the tumor regions. The contrast-to-noise ratio (CNR) between tumor and white matter increased from 0.8 +/- 0.2 to 1.3 +/- 0.3 with tumor grade. In patients with an identified muscular (23)Na channelopathy (Paramyotonia congenita (PC)), induced muscle weakness led to a signal increase of approximately 18% in the (23)Na MR images, which was attributed to intracellular Na(+) accumulation in this region.
authors.affiliation: Medical Physics in Radiology, Deutsches Krebsforschungszentrum, Heidelberg, Germany. sonia.nielles-vallespin@siemens.com
authors.forename: Sònia
authors.initials: S
authors.lastname: Nielles-Vallespin
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Weber
authors.forename: Michael
authors.initials: M
authors.lastname: Bock
authors.forename: André
authors.initials: A
authors.lastname: Bongers
authors.forename: Peter
authors.initials: P
authors.lastname: Speier
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
authors.forename: Johannes
authors.initials: J
authors.lastname: Wöhrle
authors.forename: Frank
authors.initials: F
authors.lastname: Lehmann-Horn
authors.forename: Marco
authors.initials: M
authors.lastname: Essig
authors.forename: Lothar R
authors.initials: LR
authors.lastname: Schad
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D005240:Feasibility Studies; D005910:Glioma / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D020967:Myotonic Disorders / Q000175:diagnosis* / Q000378:metabolism; D010865:Pilot Projects; D012016:Reference Values; D012964:Sodium / Q000032:analysis / Q000378:metabolism*; D012975:Sodium Isotopes
chemical_list: D012975:Sodium Isotopes; D012964:Sodium