M.Sc. Yannick Lutz

B.Sc. Tobias Meißner

Overview
In western countries, stroke is the third-most widespread cause of death. 80% of all strokes are ischemic and caused by a cerebral thrombosis or an embolism. The mortality rate of ischemic strokes is about 25%, while 35–55% of affected patients experience permanent disability. Therapeutic hypothermia (TH) showed neuroprotective effect and can possibly decrease the stroke induced cerebral damage. Recently, an intracarotid cooling sheath was developed to induce local TH in the penumbra using the cooling effect of cranial blood flow via collaterals. Unfortunately, so far, the control and regulation of the temporal and spatial cerebral temperature course is connected to invasive temperature measurements. Computational modelling provides unique opportunities to predict the resulting temperature decrease of the brain tissue and could replace the invasive procedure.

Task
The aim of this work is the adaption of a realistic brain geometry to use it for temperature calculation. In this context, the geometry will be divided into functional and perfusion areas. For the underlying necessary subdivision of the tetrahedron mesh an algorithm following the idea of region growing shall be developed. Considering the composition of white and grey matter in the extracted perfusion areas, the existing hemodynamics model will be updated and adapted. For a realistic assignment of the arteries, a literature research will be performed.
The actual temperature calculation will be performed in COMSOL® using the Bio-Heat-exchange package. In multiple simulations resulting spatial brain temperatures will be calculated in case of ischemic stroke varying the performances of the cooling sheath and the degree of cerebral collateralization.