Voxel‐based analysis of whole brain FLAIR at 3T detects focal cortical dysplasia

Abstract

SUMMARYBackground: Focal Cortical Dysplasia (FCD) is an important cause for pharmacoresistant epilepsy that can be treated surgically. The identification of the abnormal cortex on standard MRI can be difficult and computational techniques have been developed to increase sensitivity. In this study we evaluate the potential of a novel whole-brain voxelbased technique using normalized FLAIR signal intensity (nFSI) at 3 Tesla. Methods: Twenty-five patients with neuroradiologically reported FCD were included and compared to 25 healthy control subjects using Statistical Parametric Mapping (SPM5). T 2 FLAIR scans were intensity normalized and each individual patient was compared against the control group. Each control subject was compared against the remaining control group.

Magnetic resonance imaging of focal cortical dysplasia: Comparison of 3D and 2D fluid attenuated inversion recovery sequences at 3T

“…We speculate that a potential of the 3D FLAIR sequence would be the use in automated techniques for the detection of FCDs in voxelbased analyses, where 2D-FLAIR sequences have been proven to be helpful (Focke et al, 2008(Focke et al, , 2009Wagner et al, 2011). An additional advantage of 3D imaging is the possibility to visualize the cortex using 3D surface rendering techniques.…”

“…FLAIR imaging has proven to be advantageous in the diagnostic workup of epilepsy patients (Focke et al, 2008(Focke et al, , 2009Knake et al, 2005;Saini et al, 2010;Urbach et al, 2002). Still, using 2D sequences, the necessity to perform scans in three orthogonal planes, affords a long scan time (approx.…”

“…Despite the use of high resolution MR imaging protocols, approximately 25-35% of the FCDs are unrecognized (Krsek et al, 2008;Lerner et al, 2009). Recently, advances in MR with dedicated surface coils (Knake et al, 2005) or post-processing techniques with automated lesion detection (Focke et al, 2008;Huppertz et al, 2008;Wagner et al, 2011) have improved the detection rate of FCDs. Imaging at higher field strengths and the use of new imaging sequences such as diffusion tensor imaging (Widjaja et al, 2007) and positron emission tomography studies (Salamon et al, 2008) further increased yield.…”

Neuroimaging in Epileptic Disorders

“…Modern 3T MRI scanner and sequences can identify focal abnormalities or clarify uncertain findings previously observed (Strandberg et al, 2008). A voxel-based analysis of FLAIR signal intensity detected malformations of cortical development in individual patients, suggesting that this method may be a useful adjunct to the visual reading of MRI scans (Focke et al, 2008). Recent advances in MRI acquisition, such as the PROPELLER sequence, give improved spatial resolution and definition of hippocampal substructures in vivo (Eriksson et al, 2008).…”

Linking MRI post-processing with Magnetic source imaging in MRI-negative epilepsy

“…[8][9][10] Many advanced image processing strategies have been investigated to improve the detection of subtle cortical abnormalities in the epileptogenic zone that might escape conventional visual analysis. 11 These strategies include curvilinear reformatting of 3D MRI, [12][13][14] , texture analysis, [15][16][17] quantitative voxel-based intensity analysis, [18][19][20] cortical thickness analysis, 21 sulcal morphometric analysis 22 and quantification of gray and white matter distribution by voxel-based morphometry. [23][24][25][26][27][28][29] Among them, a voxel-based MRI morphometric analysis program (MAP), implemented using parametric mapping software (SPM), has been used to detect subtle cortical malformations with a high degree of sensitivity.…”