Enhanced visualization of blurred gray-white matter junctions in focal cortical dysplasia by voxel-based 3D MRI analysis.
OBJECTIVE
Focal cortical dysplasia (FCD), a frequent cause of partial epilepsy, is often associated with blurring of the gray-white matter junction in magnetic resonance images (MRI). To improve the recognition and delineation of FCD we developed a novel voxel-based image post-processing method for enhanced visualization of blurred gray-white matter junctions.


METHODS
Using standard algorithms of statistical parametric mapping software (SPM99) a T1-weighted MRI volume data set is normalized and segmented. The distribution of gray and white matter is analyzed on a voxelwise basis and compared with a normal database. Based on this analysis, a three-dimensional feature map is created which highlights brain areas with blurred gray-white matter transition. This method was applied to the MRI data of 25 epilepsy patients with histologically proven FCD.


RESULTS
In 18/25 patients the new feature maps clearly showed that the dysplastic lesions were accompanied by blurring of the gray-white matter junction. Combined with a formerly published method of voxel-based 3D MRI analysis, 21/25 FCD lesions were shown to be associated with either blurring or abnormal extension of gray matter beyond the normal cortical ribbon, including four cases with lesions not or incompletely recognized on conventional MRI.


CONCLUSIONS
The MRI post-processing presented here improves the visualization of FCD and may increase the diagnostic yield of MRI. Thereby, it provides a valuable additional diagnostic tool in the presurgical evaluation of epilepsy patients.
Huppertz
Hans-Jürgen
HJ
Epilepsy Center, University Hospital Freiburg, Breisacher Str. 64, 79106 Freiburg, Germany. huppertz@nz.ukl.uni-freiburg.de
Grimm
Christina
C
Fauser
Susanne
S
Kassubek
Jan
J
Mader
Irina
I
Hochmuth
Albrecht
A
Spreer
Joachim
J
Schulze-Bonhage
Andreas
A
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000002:abnormalities* / Q000473:pathology*; D002648:Child; D004827:Epilepsy / Q000473:pathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies