Quantification of absolute blood flow in tissue using fluorescence mediated photoplethysmography

A system for quantifying absolute blood flow through a tissue volume, the system comprising one or more processors configured to execute instructions to cause the system to:

• obtain a sequence of angiographic images of a tissue volume following administration of a volume of a fluorescence dye into vasculature supplying the tissue volume;
• calculate average fluorescence intensities for the sequence of angiographic images of the tissue volume;
• generate a plot of time-varying average fluorescence intensity;
• determine an increase in thickness of a blood volume layer based on the plot of time-varying average fluorescence intensity and based on a graph of fluorescence intensity versus capillary diameter;
• and
• determine absolute blood flow based in part on the determined increase in thickness of the blood volume layer.

A non-transitory computer-readable storage medium storing instructions for quantifying absolute blood flow through a tissue volume, the instructions configured to be executed by a system comprising one or more processors to cause the system to:

• obtain a sequence of angiographic images of a tissue volume following administration of a volume of a fluorescence dye into vasculature supplying the tissue volume;
• calculate average fluorescence intensities for the sequence of angiographic images of the tissue volume;
• generate a plot of time-varying average fluorescence intensity;
• determine an increase in thickness of a blood volume layer based on the plot of time-varying average fluorescence intensity and based on a graph of fluorescence intensity versus capillary diameter;
• and
• determine absolute blood flow based in part on the determined increase in thickness of the blood volume layer.