Abstract: The various aspects relate to a method of determining a geometrical parameter of a side branch of a main branch of a blood vessel, comprising receiving a multitude of cross section data sets, the data sets representing geometries of cross sections of the main branch over a length of the main branch and receiving position data of a cut plane of the main branch, the cut plane intersecting the side branch and the cut plane being defined under an angle with the cross-sections. The method further comprises, based on data in at least a part of the cross section data sets, constructing image data of a constructed cross section of the main branch in the cut plane. The method comprises receiving contour data defining a contour in the constructed cross section, the contour being provided in the side branch and determining the parameter by determining a parameter of the contour.

Abstract: Deviations of blood pressure due to stenosis caused by plaque pose a health risk. The deviation, often expressed in a fractional flow reserve, may be calculated on a per-location basis using deviations of the local cross-sectional area or local diameter from a reference value representing a healthy vessel. The reference value may be obtained by means of linear or higher order interpolation or linear regression techniques. Together with the flow velocity of a fluid through the vessel, a value of local deviation of a vessel geometry compared to a reference value allows for accurate, fast and efficient calculation of the fractional flow reserve for every location of the vessel for which geometry data is available. The reference value as well as actual data obtained by measurements may be represented or approximated by functions, allowing accurate and efficient calculation of data over a continuous region of the segment under scrutiny.

Abstract: The various aspects relate to a method of determining a geometrical parameter of a side branch of a main branch of a blood vessel, comprising receiving a multitude of cross section data sets, the data sets representing geometries of cross sections of the main branch over a length of the main branch and receiving position data of a cut plane of the main branch, the cut plane intersecting the side branch and the cut plane being defined under an angle with the cross-sections. The method further comprises, based on data in at least a part of the cross section data sets, constructing image data of a constructed cross section of the main branch in the cut plane. The method comprises receiving contour data defining a contour in the constructed cross section, the contour being provided in the side branch and determining the parameter by determining a parameter of the contour.