MR Imaging of the Human Brain at 1.5 T: Regional Variations in Transverse Relaxation Rates in the Cerebral Cortex
Christos S. Georgiadesa,
Ryuta Itoha,
Xavier Golaya,
Peter C. M. van Zijla and
Elias R. Melhema
a From the Department of Radiology and Radiological Sciences (C.S.G., R.I., P.C.M.v.Z., E.R.M.), The Johns Hopkins Medical Institution, and the F.M. Kirby Functional Research Center for Functional Brain Imaging (R.I., X.G., P.C.M.v.Z., E.R.M.), Kennedy Krieger Institute, Baltimore, MD.
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FIG 1. First-echo oblique coronal MR images (1000/25) of the brain, with variably sized ROIs placed in the insular cortex (arrow) and hippocampus (arrowheads).
a, Multiecho 3D CPMG image obtained in a healthy volunteer at the level of the frontal horns of the lateral ventricles.
b, Corresponding pixel-by-pixel T2 map.
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FIG 2. First-echo oblique coronal MR images (1000/25) of the brain, with variably sized ROIs placed in the primary auditory cortex (arrow).
a, Multiecho 3D CPMG image obtained in a healthy volunteer at the level of the bodies of the lateral ventricles.
b, Corresponding pixel-by-pixel T2 map.
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FIG 3. Bar graph of the mean T2 relaxation times in one deep gray matter region, the caudate nucleus (CN), and nine cortical regions: primary auditory cortex (PAC), primary visual cortex (PVC), superior temporal gyrus (STG), superior frontal gyrus (SFG), inferior temporal gyrus (ITG), middle temporal gyrus (MTG), insula cortex (IC), cingulate gyrus (CG), and hippocampus (HH). On the basis of the T2 values, the gray matter structures can be divided into four statistically different groups
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