Computer-implemented method, computer program and diagnostic system, in particular for determining at least one geometric feature of a section of a blood vessel

A computer-implemented method for determining a length of a contiguous pixel line in an image, the method comprising:

• post-processing the contiguous pixel line by adapting connecting structures of pixels along the contiguous pixel line on a basis of a pixel neighborhood thereof;
• decomposing the post-processed contiguous pixel line into a plurality of contiguous segments on the basis of a criterion;
• fitting a corresponding parametric continuous function to each of the plurality of segments of the contiguous post-processed pixel line by adapting function parameters such that an overall curve formed from the fitted parametric continuous functions is C1-continuous at each point;
• and,
• ascertaining the length of the contiguous pixel line as a sum of arc lengths of the parametric continuous functions which are fitted to the plurality of segments of the contiguous pixel line.

A computer program having program code stored on a non-transitory computer readable medium, said program code being configured, when executed by a processor, to:

• provide at least one image of a section of a blood vessel in an operating region;
• determine an adapted blood vessel model for the section of the blood vessel by adapting a blood vessel model, which describes the section of the blood vessel as a flow channel with a wall delimiting the flow channel and with an axis of symmetry, via image processing using at least one of the images provided;
• ascertain a relative spatial position of a side of the wall of the section of the blood vessel which delimits the flow channel and which faces the axis of symmetry in the at least one image provided;
• determine a centerline of the section of the blood vessel in a form of a contiguous pixel line in the at least one image provided from the relative spatial position of the side of the wall of the section of the blood vessel which delimits the flow channel and which faces the axis of symmetry;
• derive the at least one geometric feature of the section of the blood vessel in the operating region from the adapted blood vessel model;
• post-process the centerline by adapting connecting structures of pixels along the contiguous pixel line on a basis of pixel neighborhoods thereof;
• decompose the post-processed centerline into a plurality of contiguous segments on a basis of a criterion;
• and,
• fit a corresponding parametric continuous function to each of the plurality of segments of the post-processed centerline by adapting function parameters such that an overall curve formed from the fitted parametric continuous functions is C1-continuous at each point.

A system for determining at least one geometric feature of a section of an object, wherein the object is a blood vessel in an operating region, the at least one feature being at least one of length, wall thickness, internal diameter and external diameter of a section of a blood vessel, the system comprising:

• a device for providing at least one image of the section of the object;
• a non-transitory computer readable storage medium;
• and
• a computer unit including a processor;
• program code stored on said non-transitory computer readable storage medium;
• said program code being configured, when executed by said processor, to:
• provide at least one image of the section of the object;
• determine an adapted blood vessel model for the section of the blood vessel by adapting a blood vessel model, which describes the section of the blood vessel as a flow channel with a wall delimiting the flow channel and with an axis of symmetry, via image processing using at least one of the images provided;
• ascertain a relative spatial position of a side of the wall of the section of the blood vessel which delimits the flow channel and which faces the axis of symmetry in the at least one image provided;
• determine a centerline of the section of the blood vessel in a form of a contiguous pixel line in the at least one image provided from the relative spatial position of the side of the wall of the section of the blood vessel which delimits the flow channel and which faces the axis of symmetry;
• derive the at least one geometric feature of the section of the blood vessel in the operating region from the adapted blood vessel model;
• post-process the centerline by adapting connecting structures of pixels along the contiguous pixel line on a basis of pixel neighborhoods thereof;
• decompose the post-processed centerline into a plurality of contiguous segments on a basis of a criterion;
• and,
• fit a corresponding parametric continuous function to each of the plurality of segments of the post-processed centerline by adapting function parameters such that an overall curve formed from the fitted parametric continuous functions is C1-continuous at each point.