Quantification of sodium T1 in abdominal tissues at 3 T

MAGMA. 2020 Jun;33(3):439-446. doi: 10.1007/s10334-019-00786-8. Epub 2019 Oct 17.

Abstract

Introduction: Although relevant for assessment of sodium in multiple endocrine pathways, 23Na-T1 quantification is challenging due to technical limitations (SAR, B1 inhomogeneity) or influence of tissue's local molecular dynamics. Hereby, we propose T1 quantification of 23Na-MRI signal acquired over the abdomen using a centric-reordered saturation-recovery (SR) true fast imaging with steady state precession (TrueFISP) sequence.

Materials and methods: Measurements were performed at 3T using a dual-tunable 23Na/1H coil in 7 healthy volunteers (TR/TE = 858-928/1.57 ms; flip angle = 90°; bandwidth = 450 Hz/px; voxel size = 5 × 5 × 10 mm3). Variable T1-weighting was achieved applying non-selective saturation pre-pulses delayed from the centre of the k-space acquisition by 25, 40, 60, 120 and 250 ms. T1-curve fitting was performed slice-wise, separately for average intensity values from the manually segmented areas of the renal parenchyma and spinal canal, over the increasing SR times- assuming monoexponential signal pattern.

Results: Mean ± standard deviation of 23Na-T1 was found as 29 ± 10 ms and 35 ± 8 ms for the renal parenchyma and the spinal canal, respectively.

Discussion: 23Na-T1 quantification using a SR-TrueFISP is feasible in clinical settings, in the images constrained by clinically applicable acquisition time of reduced spatial resolution or averages.

Keywords: 23Na; 3D SR-TrueFISP; Clinical MRI; Sodium T1.

MeSH terms

  • Abdomen
  • Adult
  • Algorithms
  • Calibration
  • Computer Simulation
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / methods
  • Image Processing, Computer-Assisted / methods*
  • Imaging, Three-Dimensional
  • Magnetic Resonance Imaging / methods*
  • Male
  • Normal Distribution
  • Phantoms, Imaging
  • Reproducibility of Results
  • Signal-To-Noise Ratio
  • Sodium
  • Sodium Isotopes*
  • Water / chemistry

Substances

  • Sodium Isotopes
  • Water
  • Sodium