Detection of epileptogenic cortical malformations with surface-based MRI morphometry. PLoS One 2011 Feb 04;6(2):e16430
Date
02/18/2011Pubmed ID
21326599Pubmed Central ID
PMC3033882DOI
10.1371/journal.pone.0016430Scopus ID
2-s2.0-79951531923 (requires institutional sign-in at Scopus site) 68 CitationsAbstract
Magnetic resonance imaging has revolutionized the detection of structural abnormalities in patients with epilepsy. However, many focal abnormalities remain undetected in routine visual inspection. Here we use an automated, surface-based method for quantifying morphometric features related to epileptogenic cortical malformations to detect abnormal cortical thickness and blurred gray-white matter boundaries. Using MRI morphometry at 3T with surface-based spherical averaging techniques that precisely align anatomical structures between individual brains, we compared single patients with known lesions to a large normal control group to detect clusters of abnormal cortical thickness, gray-white matter contrast, local gyrification, sulcal depth, jacobian distance and curvature. To assess the effects of threshold and smoothing on detection sensitivity and specificity, we systematically varied these parameters with different thresholds and smoothing levels. To test the effectiveness of the technique to detect lesions of epileptogenic character, we compared the detected structural abnormalities to expert-tracings, intracranial EEG, pathology and surgical outcome in a homogeneous patient sample. With optimal parameters and by combining thickness and GWC, the surface-based detection method identified 92% of cortical lesions (sensitivity) with few false positives (96% specificity), successfully discriminating patients from controls 94% of the time. The detected structural abnormalities were related to the seizure onset zones, abnormal histology and positive outcome in all surgical patients. However, the method failed to adequately describe lesion extent in most cases. Automated surface-based MRI morphometry, if used with optimized parameters, may be a valuable additional clinical tool to improve the detection of subtle or previously occult malformations and therefore could improve identification of patients with intractable focal epilepsy who may benefit from surgery.
Author List
Thesen T, Quinn BT, Carlson C, Devinsky O, DuBois J, McDonald CR, French J, Leventer R, Felsovalyi O, Wang X, Halgren E, Kuzniecky RAuthor
Chad Carlson MD Professor in the Neurology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultBrain Mapping
Cerebral Cortex
Child
Electroencephalography
Epilepsy
Female
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Male
Middle Aged
Nervous System Malformations
Radiography
Retrospective Studies
Sensitivity and Specificity
Young Adult
