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Quality of 186 child brain spectra using motion and B0 shim navigated single voxel spectroscopy
Author(s) -
Hess Aaron T.,
Kouwe André J.W.,
Mbugua Kenneth K.,
Laughton Barbara,
Meintjes Ernesta M.
Publication year - 2014
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24436
Subject(s) - shim (computing) , voxel , nuclear medicine , repeatability , nuclear magnetic resonance , laser linewidth , physics , mathematics , medicine , radiology , optics , statistics , laser , erectile dysfunction
Purpose To evaluate B0 shim and motion navigated single voxel spectroscopy in children. Assess the repeatability of metabolite concentrations in three regions: medial frontal grey matter, peritrigonal white matter, and basal ganglia. Determine the extent of intra‐ and interacquisition movement in this population. Methods Linewidth and signal to noise ratio were calculated to assess spectral quality of 186 spectra at 3 Tesla. Repeatability was assessed on 31 repeat scans. Navigator images were used to assess localization errors, while navigator motion and shim logs were used to demonstrate the efficacy of correction needed during the scans. Results Average linewidths ± standard deviations of N‐acetyl aspartate are 3.8 ± 0.6 Hz, 4.4 ± 0.5 Hz, and 4.7 ± 0.8 Hz in each region, respectively. Scan‐to‐scan measurement variance in metabolite concentrations closely resembled the expected variance. A total of 73% and 32% of children moved before and during the acquisition, causing a voxel shift of more than 10% of the voxel volume, 1.5 mm. The predominant movement directions were sliding out of the coil and nodding (up–down rotation). First‐order B0 corrections were significant (>10 μT/m) in 18 % of acquisitions. Conclusion Prospective motion and B0 correction provides high quality repeatable spectra. The study found that most children moved between acquisitions and a substantial number moved during acquisitions. J. Magn. Reson. Imaging 2014;40:958–965 . © 2013 Wiley Periodicals, Inc .