Winthrop Prof. Karol Miller – Patient-Specific Solution of the Electrocorticography Forward Problem in Deforming Brain

Abstract

When one types “epilepsy” in the Google window the statement “Treatment can help, but this condition can’t be cured” appears. This is not true, as it is well known that precisely targeted surgery is a curative treatment. Why is then surgical treatment of epilepsy “arguably the most underutilised of all proven effective therapeutic interventions in the field of medicine”? The catch is in “precisely targeted” – clinicians are often unable to characterise epileptic activity of the brain and identify appropriate resection regions with sufficient accuracy to proceed with surgery.

In this seminar I will discuss work in progress (conducted in collaboration with Boston Children’s Hospital) towards developing methods to precisely and reliably locate seizure onset zones (SOZ) and visualise them with respect to pre-operative brain anatomy in a system to improve intra-operative visualisation, navigation and monitoring. The approach consists of taking a pre-operative 3D MRI; implanting intracranial electrodes; taking a CT with electrodes implanted; registering pre-operative 3D MRI onto a CT with implanted electrodes; and finally solving inverse electric field propagation problem to identify SOZ.

From the computational science view point the problematic issues include:

i) computing patient-specific brain deformations due to insertion of invasive electrodes,

ii) using these deformations to warp pre-operative MRIs so that they correspond to the brain with implanted electrodes,

iii) creating a patient-specific distribution of anisotropic electrical conductivity based on diffusion tensor images,

iv) solving the (linear, but highly anisotropic and inhomogeneous) bio-electric potential distribution problem.

Methods for all the above should be compatible with clinical workflows and therefore software embedding these methods should be very robust so that it can be used by non-specialists in the clinic.

If you are interested in methodological details of this presentation, please read our preprint https://arxiv.org/abs/2109.07164 .