A double-tuned1H/23Na dual resonator system for tissue sodium concentration measurements in the rat brain via Na-MRI

Wetterling, F., Tabbert, M., Junge, S., Gallagher, L., Macrae, I.M. and Fagan, A.J. (2010) A double-tuned1H/23Na dual resonator system for tissue sodium concentration measurements in the rat brain via Na-MRI. Physics in Medicine and Biology, 55(24), pp. 7681-7695. (doi: 10.1088/0031-9155/55/24/019)

Abstract

A method for quantifying the tissue sodium concentration (TSC) in the rat brain from Na-23-MR images was developed. TSC is known to change in a variety of common human diseases and holds considerable potential to contribute to their study; however, its accurate measurement in small laboratory animals has been hindered by the extremely low signal to noise ratio (SNR) in Na-23 images. To address this, the design, construction and characterization of a double-tuned H-1/Na-23 dual resonator system for H-1-guided quantitative Na-23-MRI are described. This system comprises an SNR-optimized surface detector coil for Na-23 image acquisition, and a volume resonator producing a highly homogeneous B-1 field (<5% inhomogeneity) for the Na channel across the rat head. The resonators incorporated channel-independent balanced matching and tuning capabilities with active decoupling circuitry at the Na-23 resonance frequency. A quantification accuracy of TSC of <10 mM was achieved in Na-images with 1.2 mu l voxel resolution acquired in 10 min. The potential of the quantification technique was demonstrated in an in vivo experiment of a rat model of cerebral stroke, where the evolution of the TSC was successfully monitored for 8 h after the stroke was induced.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gallagher, Mrs Lindsay and Macrae, Professor Mhairi
• Authors: Wetterling, F., Tabbert, M., Junge, S., Gallagher, L., Macrae, I.M., and Fagan, A.J.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Physics in Medicine and Biology
• ISSN: 0031-9155