Stability metrics for optic radiation tractography

Stability metrics for optic radiation tractography: Towards damage prediction after resective surgery

Meesters, Stephan (Maastricht UMC; Eindhoven University of Technology)
Ossenblok, Pauly (Maastricht UMC; Eindhoven University of Technology)
Wagner, Louis (Maastricht UMC)
Schijns, Olaf (Maastricht UMC)
Boon, Paul (Maastricht UMC)
Florack, Luc (Eindhoven University of Technology)
Vilanova Bartroli, A. (TU Delft Computer Graphics and Visualisation; Eindhoven University of Technology)
Duits, Remco (Eindhoven University of Technology)

2017

Background An accurate delineation of the optic radiation (OR) using diffusion MR tractography may reduce the risk of a visual field deficit after temporal lobe resection. However, tractography is prone to generate spurious streamlines, which deviate strongly from neighboring streamlines and hinder a reliable distance measurement between the temporal pole and the Meyer's loop (ML-TP distance). New method Stability metrics are introduced for the automated removal of spurious streamlines near the Meyer's loop. Firstly, fiber-to-bundle coherence (FBC) measures can identify spurious streamlines by estimating their alignment with the surrounding streamline bundle. Secondly, robust threshold selection removes spurious streamlines while preventing an underestimation of the extent of the Meyer's loop. Standardized parameter selection is realized through test–retest evaluation of the variability in ML-TP distance. Results The variability in ML-TP distance after parameter selection was below 2 mm for each of the healthy volunteers studied (N = 8). The importance of the stability metrics is illustrated for epilepsy surgery candidates (N = 3) for whom the damage to the Meyer's loop was evaluated by comparing the pre- and post-operative OR reconstruction. The difference between predicted and observed damage is in the order of a few millimeters, which is the error in measured ML-TP distance. Comparison with existing method(s) The stability metrics are a novel method for the robust estimate of the ML-TP distance. Conclusions The stability metrics are a promising tool for clinical trial studies, in which the damage to the OR can be related to the visual field deficit that may occur after epilepsy surgery.

Diffusion magnetic resonance imaging
Epilepsy
Fiber tractography
Meyer's loop
Neurosurgery
Optic radiation

http://resolver.tudelft.nl/uuid:1048e3bd-ccfa-44e8-a63b-9475bf57dffe

https://doi.org/10.1016/j.jneumeth.2017.05.029

0165-0270

Journal of Neuroscience Methods, 288, 34-44

Institutional Repository

journal article

© 2017 Stephan Meesters, Pauly Ossenblok, Louis Wagner, Olaf Schijns, Paul Boon, Luc Florack, A. Vilanova Bartroli, Remco Duits