Quantifying Blood Volume Flow Using Optical Methods

In patients undergoing vascular surgeries such as bypass grafting, the use of intraoperative blood flow measurements has proven to be effective in reducing recurrence rates. Our research focuses on quantifying blood volume flow using optical methods, specifically fluorescence angiography and optical coherence tomography angiography (OCTA).

Indocyanine green (ICG) fluorescence angiography (FA) is a camera-based method. At our Institute, we've established an end-to-end workflow integrating clinical video data to derive quantitative flow values. The calculation of flow entails determining the transit time of a bolus across a specified distance and defining the vessel's cross-sectional area. Within this project, our aim is to identify and quantify potential measurement errors, intending to enhance the pipeline's robustness and efficiency.

OCTA is a non-contact technique used to visualize vascular flow based on erythrocyte motion and scattering. Hence, repeated Optical Coherence Tomography (OCT) scans are conducted to detect motion contrast and visualize the vasculature. Despite OCTA being utilized in clinical settings, it predominantly serves as a qualitative tool. Currently, there is no available quantitative blood flow assessment based on OCT hardware and OCTA algorithms. Therefore, the limitations of OCTA are explored in OCTA. The objective is to establish a quantitative correlation between the OCTA signal and blood flow in large vessels by measuring this signal at a specific location in the vessel.