Toward Real-time Dye-free Noninvasive Intra-operative Monitoring of Cerebral Perfusion. (16th November 2020)

• Record Type: Journal Article
• Authors: Florence, T J; Samarage, Hasitha M; Wang, Anthony C
• Is Part Of: Neurosurgery. Volume 67(2010)Supplement 1
• Publication Date: 2020-11-16
• Subjects: Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1093/neuros/nyaa447_239
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract: INTRODUCTION: Cerebrovascular surgery demands the precise manipulation of cerebral blood flow. For intracranial bypass, imprecise manipulation carries significant consequences: sustained hypoperfusion will infarct tissue, while dysregulated hyperperfusion can lead to transient or permanent neurological deficit. Current techniques for guiding intraoperative control of cerebral perfusion indirectly measure vessel flow. Perivascular sonography measures flow through relatively large vessels, and fluorescent methods demonstrate vessel patency in a largely binary manner. No intraoperative techniques measure brain parenchymal perfusion per se. Cerebrovascular surgery generally, and extracranial-intracranial bypass specifically, would benefit from such a method. Here we present initial work on a computational method to recover relative changes in cerebral parenchymal perfusion using algorithmic amplification of digital video from operative microscopes. METHODS: In brief, a video sequence is decomposed into multiple spatial frequency bands and then temporally filtered about frequencies of interest (0.8-4 Hz). The extracted signal is then multiplied by a gain factor and superimposed on the original video. Change in putative perfusion signal over adjacent neocortex is compared before and after completion of the bypass. RESULTS: In a sample of seven patients, we observe reliably increased perfusion signal following bypass (mean 57%, range 8–151%) after application of EVM. CONCLUSION: Eulerian video magnification represents a promising method toward realizing real-time, dye-free intraoperative brain perfusion estimation in a manner unobtrusive to the procedure. In ongoing work we are evaluating our method against established techniques (e.g. angiography, MR perfusion) for evaluating local cerebral perfusion.