Abstract
BACKGROUND AND PURPOSE: Our goal was to develop a novel technique for measuring a small number of localized spectra simultaneously and in a time-efficient manner.
MATERIALS AND METHODS: Using appropriate radiofrequency pulses, the magnetization from multiple voxels is excited simultaneously and then separated (reconstructed) by using the individual coil-sensitivity profiles from a multichannel receiver coil. Because no gradients are used for k-space encoding, constrained source space MR spectroscopy provides a time advantage over conventional spectroscopic imaging and an improved signal-to-noise ratio per square root of unit time over single-voxel spectroscopy applied at each successive location. In the present work, we considered prototype application of constrained source space MR spectroscopy for 2 voxels.
RESULTS: Experimental data from healthy volunteers and simulation results showed that constrained source space MR spectroscopy is effective at extracting 2 independent spectra even in the challenging scenario of the voxels being closely spaced. Also, from 6 patients with various types of brain cancer we obtained 2-voxel constrained source space MR spectroscopy data, which showed spectra of clinical quality in half the time required to perform successive single-voxel MR spectroscopy.
CONCLUSIONS: Constrained source space MR spectroscopy provides clinical quality spectra and could be used to probe multiple voxels simultaneously in combination with Hadamard encoding for further scan-time reductions.
Abbreviations
- CSSMRS
- constrained source space MR spectroscopy
- PRESS
- point-resolved spectroscopy sequence
- SVS
- single-voxel spectroscopy
- © 2015 American Society of Neuroradiology