Fractional flow reserve determination

A method for fractional flow reserve determination, the method comprising the steps of:

• generating a three-dimensional model of an imaged vascular vessel tree surrounding a stenosed vessel segment by a processor, based on a segmentation of only the stenosed vessel segment and one or more branches distal to the stenosed vessel segment of the imaged vascular vessel tree, the vascular vessel tree comprising one or more branches proximal to the stenosed vessel segment and the one or more branches distal to the stenosed vessel segment;
• calculating a blood flow rate through the stenosed vessel segment based on an analysis of a time-series of X-ray images of the vascular vessel tree by the processor, wherein the analysis includes:
• calibrating the time-series of X-ray images, wherein the calibrating comprises:
• removing scatter and background structures from the time-series of X-ray images;
• and
• calibrating an intensity of the time-series of X-ray images based on at least one of a phantom with a known attenuation or information associated with the three-dimensional model;
• determining a curve representative of the intensity over time in the calibrated time-series of X-ray images;
• and
• determining, as the blood flow rate, a slope of the curve at a time of contrast bolus arrival at only a region distal to the stenosed vessel segment;
• determining a fractional flow reserve based on the three-dimensional model and the calculated blood flow by the processor;
• and
• outputting, by the processor, the fractional flow reserve for display at a display device in communication with the processor.