Prof. Dr. Igor Meglinski (Aston U): Enhancing surgical precision: breakthroughs in dynamic light scattering for intraoperative imaging

Date of publication: 14. 3. 2024
Monday physics colloquium
14:15 - 15:15

The majority of biological tissues are the highly heterogeneous media composing mixture of static (e.g. skin, bones) and dynamic (e.g. blood, lymph) structural inclusions. The presence of static areas exhibit non-ergodic features providing systematic uncertainty in the quantitative interpretation of the measurements of Dynamic Light Scattering (DLS). In fact, a number of various DLS-based techniques are extensively used for monitoring, imaging and quantitative assessment of blood flows in biological tissues, whereas the issues associated with the non-ergodicity are typically ignored. Based on the simple phenomenological model we present a justification for the applicability of DLS-based imaging technique for monitoring of blood flows within brain tissues under the formally broken ergodicity conditions. Taking into account that DLS recording images are nonstationary and the statistical properties might variate over a time of measurements, the continuous wavelet transform (CWT) is applied to explore whether the cerebral hemodynamic patterns of possible spatial or temporal synchronization across the brain surface emerged. In addition, Non-negative Matrix Factorization (NMF) is used for segmentation of DLS-based images, consequent identification of interpretable relationships within the distinct demarcated microstructure patterns and their functional evaluation. In addition, we introduce a time-space Fourier Kappa-Omega filtering approach for stabilization of fast dynamic brain images in vivo [1]. The results of evaluation of impairments of cerebral blood flow and blood microcirculation brought by acute hypoxia provoked by a poor respiration arrest and cardiac cessation are presented [2]. Finally, translating from bench to bedside, the DLS results for assessing blood flow in standard cerebrovascular surgery situations involving the common carotid arteries proximal occlusion, trapping, reperfusion, anastomosis and intraoperative vessel thrombosis are presented.
[1] G. Molodij et al., Phys. Med. Biol. 65, 075007 (2020)
[2] G. Piavchenko et al., J. Biophoton. 14, e202100216 (2021)
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