title: Sodium-23 MRI of whole spine at 3 Tesla using a 5-channel receive-only phased-array and a whole-body transmit resonator.
abstract: Sodium magnetic resonance imaging ((23)Na MRI) is a unique and non-invasive imaging technique which provides important information on cellular level about the tissue of the human body. Several applications for (23)Na MRI were investigated with regard to the examination of the tissue viability and functionality for example in the brain, the heart or the breast. The (23)Na MRI technique can also be integrated as a potential monitoring instrument after radiotherapy or chemotherapy. The main contribution in this work was the adaptation of (23)Na MRI for spine imaging, which can provide essential information on the integrity of the intervertebral disks with respect to the early detection of disk degeneration. In this work, a transmit-only receive-only dual resonator system was designed and developed to cover the whole human spine using (23)Na MRI and increase the receive sensitivity. The resonator system consisted of an already presented (23)Na whole-body resonator and a newly developed 5-channel receive-only phased-array. The resonator system was first validated using bench top and phantom measurements. A threefold SNR improvement at the depth of the spine (∼7cm) over the whole-body resonator was achieved using the spine array. (23)Na MR measurements of the human spine using the transmit-only receive-only resonator system were performed on a healthy volunteer within an acquisition time of 10minutes. A density adapted 3D radial sequence was chosen with 6mm isotropic resolution, 49ms repetition time and a short echo time of 540μs. Furthermore, it was possible to quantify the tissue sodium concentration in the intervertebral discs in the lumbar region (120ms repetition time) using this setup.
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany. Electronic address: matthias.malzacher@medma.uni-heidelberg.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Malzacher
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany.
authors.forename: Raffi
authors.initials: R
authors.lastname: Kalayciyan
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Konstandin
authors.affiliation: Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany; Department of Radiology, University Hospital of Cologne, Kerpener Str. 62, D-50937 Köln, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Haneder
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany.
authors.forename: Lothar R
authors.initials: LR
authors.lastname: Schad
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D057054:Molecular Imaging / Q000295:instrumentation; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012975:Sodium Isotopes / Q000493:pharmacokinetics*; D013131:Spine / Q000000981:diagnostic imaging* / Q000378:metabolism*; D014018:Tissue Distribution; D014159:Transducers; D051598:Whole Body Imaging / Q000295:instrumentation* / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D012975:Sodium Isotopes
keywords: Empfangsspule; Natrium-MR-Bildgebung; Sodium MRI; Wirbelsäulen-MR-Bildgebung; receive-only surface coil; spine MRI