Abstract
Introduction: Brain volume measurement is widely applied in many situations. High magnetic field magnetic resonance imaging (MRI) has an advantage in evaluating brain volume due to its high signal-to-noise ratio (SNR). However, many facilities only have low magnetic field MRI. The purpose of this study was to compare local brain volume scanned with 0.3 T MRI to that scanned with 3 T MRI.
Methods: Eighteen healthy volunteers (age 72.3±6.0 years) underwent whole-brain threedimensional (3D) T1-weighted image with 0.3 T clinical MRI system (AIRIS Vento, Hitachi)and 3 T clinical MRI system (Prisma, Siemens). The image of 0.3 T MRI was obtained using a 3D-gradient echo with inversion recovery sequence with the following parameters: TR=25 ms; TE=5.8 ms; IR=600 ms; NEX=1; FOV=200×250×250 mm2; resolution=0.98×2 mm3; total scan time=601 s.
The image of 3 T MRI was obtained using a magnetization prepared rapid gradient echo sequence with the following parameters: TR=2,300 ms; TE=2.32 ms; IR=900 ms; NEX=1; FOV=200×250×250 mm2; resolution=0.9×0.9×0.9 mm3; total scan time=321 s. The MRI data was processed using statistical parametric mapping 12 software implemented in MATLAB. The image was registered between subjects and normalized to Montreal Neurological Institute space. The signal intensity was converted to the volume. The brain was segmented to 116 regions of interest (ROIs) as listed in Automated Anatomical Labeling atlas. The volume of each ROI relative to the intracranial volume was calculated. The correlations between the local brain volume scanned with 0.3 T and that scanned with 3 T were analyzed by Pearson correlation coefficient analysis. The concordance rate of these images was also investigated.
Results: The local brain volume scanned with 0.3 T and that scanned with 3 T correlated very strongly (r=0.939). The concordance rate was higher than 80 percent in 111 out of 116 ROIs. Especially, caudate nucleus (86.98-99.92%, postcentral gyrus (78.39-99.52 %) and amygdala (90.53-99.62%) showed high concordance rates. All five ROIs with a concordance rate lower than 80 percent were in the cerebellum, and the volume of these ROIs were calculated larger in 0.3 T than in 3 T.
Conclusions: Brain volume measurement with 0.3 T MRI showed similar results to that with 3 T MRI except for some segments in the cerebellum.
© 2018 The Juntendo Medical Society. This is an open access article distributed under the terms of Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original source is properly credited.
