Dynamic Thermal Imaging for Intraoperative Monitoring of Neuronal Activity and Cortical Perfusion

Date

Dec 9, 2016

Time

10:00 AM - 11:00 AM

Speaker

Dipl.-Inf. Nico Hoffmann

Language

en

Main Topic

Informatik

Other Topics

Informatik

Description

Neurosurgery is a demanding medical discipline that requires a complex interplay of several neuroimaging techniques. This allows to recover structural as well as functional information which are then visualised to the surgeon. In case of tumour resections this approach allows more fine-grained differentiation of healthy and pathological tissue which positively influences the postoperative outcome as well as the patient's quality of living. In this work, we discuss several approaches to establish thermal imaging as novel neuroimaging technique to primarily visualize neural activity and perfusion state in case of ischaemic stroke. Both applications require novel methods for data-preprocessing, visualization, pattern recognition as well as regression analysis of intraoperative thermal imaging. Online multimodal integration of preoperative and intraoperative data is accomplished by a 2D-3D image registration and image fusion framework with average accuracy of 2.46 mm. In navigated surgeries, the proposed framework generally allows the projection of intraoperative 2D imaging data onto preoperative 3D volumetric datasets like 3D MR or CT imaging. Additionally, a fast machine learning framework for the recognition of cortical NaCl rinsings is discussed. Hereby, the standardized quantification of tissue perfusion by means of an approximative heating model is achieved. Classifying the parameters of this models yields a map of connected areas, for which we have shown that these areas correlate with the demarcation caused by an ischaemic stroke segmented in postoperative CT datasets. Finally, a semiparametric regression model was developed for intraoperative neural activity monitoring of the somatosensory cortex by somatosensory evoked potentials. These results were correlated with neural activity of optical imaging. We found that thermal imaging yields comparable results, yet doesn't share the limitations of optical imaging. With this thesis we underline that thermal imaging depicts a novel and valid tool for intraoperative functional as well as structural neuroimaging.

Last modified: Dec 9, 2016, 8:46:35 AM