Perirolandic Cortex of the Normal Brain: Low Signal Intensity on Turbo FLAIR MR Images

Abstract

On turbo FLAIR images the PRC generally has a low SI in the neurologically normal brain, and this helps as an additional landmark in identifying the sensorimotor cortex.

Generalized Multiple-Layer Appearance of the Cerebral Cortex with 3D FLAIR 7.0-T MR Imaging

“…Ex vivo experiments with fixated brain tissue have shown that the hyperintense signal does not originate from the arachnoid and that it is absent if the cortex is partly removed (19). A similar superficial hyperintensity was described in previous double inversion-recovery and turbo FLAIR studies (11,13). With inversion pulses that efficiently null the signal of the cerebrospinal fluid, this hyperintense signal of the adjacent superficial cortex becomes obvious, especially with high-resolution imaging methods with high SNR.…”

“…The most important finding in the current study was a multiple-layer appearance of the cerebral cortex in all investigated brain regions at high-resolution 3D FLAIR MR imaging at 7.0 T. Previously, at 1.5-T MR imaging, hypointensities in the perirolandic cortex were observed, but they were not observed elsewhere around the cerebral cortex (11). Similarly, a triple-layer appearance of BA 4 has been described with a thin-section double inversion-recovery MR imaging region (variance, 0.08 6 0.02), anterior frontal region (variance, 0.10 6 0.02), and occipital region (variance, 0.11 6 0.02).…”

“…Intensity profiles were obtained (J.H., a neuroradiologist with 11 years of the precentral gyrus has been observed (11,12). This hypointensity indicates that T2-weighted contrast with suppression of cerebrospinal fluid with FLAIR MR imaging may be used to discriminate between brain regions with different morphologies of the cortical layers.…”

Identification of the primary motor cortex: value of T2 echo-planar imaging, diffusion-weighted imaging and quantitative apparent diffusion coefficient measurement at 3 T

“…To define precisely the region of the PMC with the help of its characteristic features, special MR sequences have been used in vivo and in vitro at various field strengths up to 9.4 T [2,4,6,10,12,14,[19][20][21][22]. Instead of complex examinations, we have tried to localise the PMC in a simple way by using DWI, which is performed during routine MRI.…”

“…T2 shortening of the primary motor cortex (PMC) has been demonstrated both in normal adults and in patients with various neurodegenerative diseases [1][2][3][4][5]. Although the detection of T2 hypointensity depends on the field strength and the applied sequences, it has been demonstrated that T2 hypointensity is a constant finding in normal adults at 3 T using susceptibility-weighted imaging [6].…”