title: In vivo sodium MR imaging of the abdomen at 3T.
abstract: OBJECTIVE
  Transmembrane sodium ((23)Na) gradient is critical for cell survival and viability and a target for the development of anti-cancer drugs and treatment as it serves as a signal transducer. The ability to integrate abdominal (23)Na MRI in clinical settings would be useful to non-invasively detect and diagnose a number of diseases in various organ systems. Our goal in this work was to enhance the quality of (23)Na MRI of the abdomen using a 3-Tesla MR scanner and a novel 8-channel phased-array dual-tuned (23)Na and (1)H transmit (Tx)/receive (Rx) coil specially designed to image a large abdomen region with relatively high SNR.
  
  
  METHODS
  A modified GRE imaging sequence was optimized for (23)Na MRI to obtain the best possible combination of SNR, spatial resolution, and scan time in phantoms as well as volunteers. Tissue sodium concentration (TSC) of the whole abdomen was calculated from the inhomogeneity-corrected (23)Na MRI for absolute quantification. In addition, in vivo reproducibility and reliability of TSC measurements from (23)Na MRI was evaluated in normal volunteers.
  
  
  RESULTS
  (23)Na axial images of the entire abdomen with a high spatial resolution (0.3 cm) and SNR (~20) in 15 min using the novel 8-channel dual-tuned (23)Na and (1)H transmit/receive coil were obtained. Quantitative analysis of the sodium images estimated a mean TSC of the liver to be 20.13 mM in healthy volunteers.
  
  
  CONCLUSIONS
  Our results have shown that it is feasible to obtain high-resolution (23)Na images using a multi-channel surface coil with good SNR in clinically acceptable scan times in clinical practice for various body applications.
authors.affiliation: Department of Radiology, Mayo Clinic, 13400 E. Shea Blvd., Scottsdale, AZ, 85259, USA. james.judy@mayo.edu.|Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA. james.judy@mayo.edu.|School of Health Sciences, Purdue University, West Lafayette, IN, USA. james.judy@mayo.edu.
authors.forename: Judy R
authors.initials: JR
authors.lastname: James
authors.affiliation: Department of Radiology, Mayo Clinic, 13400 E. Shea Blvd., Scottsdale, AZ, 85259, USA.|Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.|School of Health Sciences, Purdue University, West Lafayette, IN, USA.
authors.forename: Anshuman
authors.initials: A
authors.lastname: Panda
authors.affiliation: Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Lin
authors.affiliation: Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.|School of Health Sciences, Purdue University, West Lafayette, IN, USA.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Dydak
authors.affiliation: Siemens Medical Solutions, MR R&D, Cary, NC, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.affiliation: Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Navin
authors.initials: N
authors.lastname: Bansal
mesh_terms: D000005:Abdomen / Q000033:anatomy & histology*; D000328:Adult; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D012975:Sodium Isotopes
chemical_list: D012975:Sodium Isotopes
keywords: 3T; Body imaging; Clinical; Liver; Sodium; Total sodium concentration