Machine Learning of DTI Structural Brain Connectomes for Lateralization of Temporal Lobe Epilepsy.
OBJECTIVE
We analyzed the ability of a machine learning approach that uses diffusion tensor imaging (DTI) structural connectomes to determine lateralization of epileptogenicity in temporal lobe epilepsy (TLE).


METHODS
We analyzed diffusion tensor and 3-dimensional (3D) T1-weighted images of 44 patients with TLE (right, 15, left, 29; mean age, 33.0 ± 11.6 years) and 14 age-matched controls. We constructed a whole brain structural connectome for each subject, calculated graph theoretical network measures, and used a support vector machine (SVM) for classification among 3 groups (right TLE versus controls, left TLE versus controls, and right TLE versus left TLE) following a feature reduction process with sparse linear regression.


RESULTS
In left TLE, we found a significant decrease in local efficiency and the clustering coefficient in several brain regions, including the left posterior cingulate gyrus, left cuneus, and both hippocampi. In right TLE, the right hippocampus showed reduced nodal degree, clustering coefficient, and local efficiency. With use of the leave-one-out cross-validation strategy, the SVM classifier achieved accuracy of 75.9 to 89.7% for right TLE versus controls, 74.4 to 86.0% for left TLE versus controls, and 72.7 to 86.4% for left TLE versus right TLE.


CONCLUSIONS
Machine learning of graph theoretical measures from the DTI structural connectome may give support to lateralization of the TLE focus. The present good discrimination between left and right TLE suggests that, with further refinement, the classifier should improve presurgical diagnostic confidence.
Department of Radiology, The University of Tokyo.
Kouhei
K
Kamiya
Shiori
S
Amemiya
Yuichi
Y
Suzuki
Naoto
N
Kunii
Kensuke
K
Kawai
Harushi
H
Mori
Akira
A
Kunimatsu
Nobuhito
N
Saito
Shigeki
S
Aoki
Kuni
K
Ohtomo
D000328:Adult; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D063132:Connectome / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D005917:Globus Pallidus / Q000473:pathology; D006179:Gyrus Cinguli / Q000473:pathology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D000069550:Machine Learning; D008297:Male; D008875:Middle Aged; D009714:Nucleus Accumbens / Q000473:pathology; D009778:Occipital Lobe / Q000473:pathology; D012189:Retrospective Studies; D060388:Support Vector Machine; D013702:Temporal Lobe / Q000473:pathology; D055815:Young Adult