Method and device for determining a geometrical parameter of a blood vessel

1. A method of determining at least one geometrical parameter of a side branch of a main branch of a blood vessel, the method comprising:

a) receiving a multitude of cross section data sets from within the blood vessel, the data sets representing geometries of cross sections of the main branch over a length of the main branch;

b) receiving position data of a cut plane of the main branch, the cut plane at least partially intersecting the side branch and the cut plane being non-parallel with the cross sections;

c) based on data in at least a part of the multitude of cross section data sets, constructing image data of a constructed cross section of the main branch in the cut plane;

d) receiving contour data defining a contour in the constructed cross section, the contour being provided in the side branch; and

e) determining the geometrical parameter by determining a geometrical parameter of the contour.

2. The method according to claim 1 , wherein the position data comprises angle data indicating an angle between the cut plane and a reference comprised by at least one of the cross section data sets.

3. The method according to claim 1 , wherein receiving the definition of the cut plane comprises:

receiving a longitudinal angle of the cut plane, the longitudinal angle being defined between the cut plane and an axis of the main branch; and

receiving a transversal angle of the cut plane, the transversal angle being defined between the cut plane and a direction perpendicular to the axis of the main branch.

4. The method according to claim 1 , wherein the position data comprises location data indicating a location of the cut plane relative to a reference point comprised by at least one of the cross section data sets.

5. The method according to claim 1 , further comprising:

based on the multitude of cross section data sets, generating first image data for display of a first two-dimensional view of the main branch in a longitudinal direction;

receiving longitudinal location data of the cut plane indicating a location of the cut plane in the first two-dimensional view;

based on the multitude of cross section data sets, generating second image data for display of a second two-dimensional view of the main branch in a transversal direction; and

receiving transversal location data of the cut plane indicating a location of the cut plane in the second two-dimensional view.

6. The method according to claim 5 , wherein generating the second image data for display also comprises incorporation of data for displaying a representation of the cut plane in the second two-dimensional view of the main branch based on the longitudinal location data.

7. The method according to claim 5 , wherein the generating the first image data for display also comprises incorporation of data for displaying a representation of the cut plane in the first two-dimensional view of the main branch based on the transversal location data.

8. The method according to claim 1 , further comprising: determining a discontinuity in a sequential series of the multitude of cross section data sets; and defining the cut plane at the location of the discontinuity as a default location.

9. The method according to claim 8 , further comprising:

determining increase of a cross section geometry parameter being above a pre-determined threshold;

determining a slope of a side of the main branch relative to a centre line of the main branch;

determining a first side of the main branch having the largest slope; and defining the cut plane to be positioned substantially perpendicular to the largest slope.

10. The method according to claim 1 , wherein the data of the cross section data sets is tomography data.

11. The method according to claim 1 , wherein the data of the cross section data sets has been obtained by means of optical coherence tomography.

12. The method according to claim 1 , wherein the data of the cross section data sets has been obtained by means of intravascular ultrasound.

13. A computer program product comprising computer executable code that, when loaded in a processing module of a computer, cause the computer to be able to execute the method according to claim 1 .

14. A device for determining at least one geometrical parameter of a side branch of a main branch of a blood vessel, the device comprising:

a data input module arranged to receive 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;

a processing unit arranged to:

receive position data of a cut plane of the main branch, the cut plane at least partially intersecting the side branch and the cut plane being non-parallel with the cross sections;

based on data in at least a part of the multitude of cross section data sets, construct image data of a constructed cross section of the main branch in the cut plane; receive contour data defining a contour in the constructed cross section, the contour being provided in the side branch; and

determine the geometrical parameter by determining a geometrical parameter of the contour.