Introduction

DTI Tractography for Neurosurgery

Diffusion-MR tractography has the potential to help neurosurgeons determine tumor resection boundaries in functional areas involving eloquent white matter pathways. However, the validity of tractography results in clinical settings has not yet been established. This workshop aims to evaluate the performances of tractography algorithms in the reconstruction of peritumoral anatomy and corticospinal tract trajectory on pre-operative and post-operative diffusion data from patients presenting with a tumor in or near the motor system.

Anatomy of the corticospinal tract

The corticospinal tract (CST) starts in the cerebral cortex and terminates in the spinal cord. The CST courses through the posterior limb of the internal capsule, the cerebral peduncle of the midbrain, the ventral pons, the ventral surface of the medulla, and decussates in the lower medulla. The picture shows the CST (white) and surrounding structures: putamen (blue), caudate nucleus (brown), lateral ventricle (green) and motor cortex (yellow).

Evaluation

The tractography submissions will be evaluated based on a set of quantitative and qualitative criteria.

The quantitative evaluation of the tracts will be performed using five metrics: * fiber profile on diffusion parameters * correlation and absolute profile distance measures * fiber geometry based on the Dice coefficient for volumetric overlap * Hausdorff distances between bundles * STAPLE sensitivity and specificity score

The qualitative evaluation of the tract reconstruction will be performed by expert neurosurgeons and radiologists. Clinical evaluation will focus on the anatomical accuracy of the corticospinal and peritumoral tract reconstructions, the presence of false-positive and false-negative tracts, and the depiction of the spatial relation between the tumor and the tracts.