Detecting and displaying stent expansion

A method for processing an intravascular image, the method comprising:

• obtaining an intravascular image acquired in an imaging modality during the pullback of the imaging catheter;
• obtaining first information indicating positions of lumen borders detected in the intravascular image and second information indicating positions of stent-struts detected in the intravascular image;
• determining a first range along the vessel in the intravascular image for evaluating stent expansion, in a stent range along the vessel where the stent is implanted;
• determining a reference value for evaluating the stent expansion based on the first information and the second information;
• determining, distributed positions along the first range, wherein each position corresponds to a different image frame of the intravascular image in which a stent-strut is detected, based on the first information and the second information;
• obtaining criterion value for evaluating a stent expansion value, which is input, selected or confirmed by a user via a user interface of the imaging modality;
• determining, at each of the distributed positions, the stent expansion value of the implanted stent, based on the second information at the position and the reference value;
• generating one or more indicators indicating one or more second ranges in the first range, based on the stent expansion value and the criterion value;
• and
• causing a display unit to display:
• an image including the range containing positions of lumen borders and positions of the stent-struts detected;
• the intravascular image including the positions of the detected lumen borders and the positions of the detected stent-struts;
• and
• the one or more indicators superimposed on the vessel image.

A non-transitory computer-readable storage medium storing a computer-readable program for causing a computer to execute a method for processing an intravascular image including a plurality of image frames acquired during a pullback of an imaging catheter inserted into a vessel, the method comprising:

• obtaining first information indicating positions of lumen borders detected in the intravascular image of the vessel and second information indicating positions of stent-struts detected in the intravascular image;
• obtaining third information indicating a first stent length independent of the intravascular image;
• calculating, based on a number of image frames in which stent-struts are detected in the intravascular image, a second stent length, wherein the second stent length corresponds to a range where a stent is implanted in the vessel;
• determining, at different positions in the range, a stent expansion value of the stent implanted in the vessel, based on the first information and the second information, wherein each image frame from image frames in which stent-struts are detected corresponds to a different position along the range;
• and
• causing a display unit to display:
• an image including positions of lumen borders and positions of the stent-struts detected;
• a first indicator indicating a level along the range, of the stent expansion value, with the vessel image;
• and
• a second indicator indicating a length difference between the first stent length and the second stent length.

A non-transitory computer-readable storage medium storing a computer-readable program for causing a computer to execute a method for processing an intravascular image, the method comprising:

• obtaining an intravascular image acquired in an imaging modality during the pullback of the imaging catheter;
• obtaining first information indicating positions of lumen borders detected in the intravascular image and second information indicating positions of stent-struts detected in the intravascular image;
• determining a first range along the vessel in the intravascular image for evaluating stent expansion, in a stent range along the vessel where the stent is implanted;
• determining a reference value for evaluating the stent expansion based on the first information and the second information;
• determining, distributed positions along the first range, wherein each position corresponds to a different image frame of the intravascular image in which a stent-strut is detected, based on the first information and the second information;
• obtaining criterion value for evaluating a stent expansion value, which is input, selected or confirmed by a user via a user interface of the imaging modality;
• determining, at each of the distributed positions, the stent expansion value of the implanted stent, based on the second information at the position and the reference value;
• generating one or more indicators indicating one or more second ranges in the first range, based on the stent expansion value being and the criterion value;
• and
• causing a display unit to display:
• an image including the vessel;
• the intravascular image including the positions of the detected lumen borders and the positions of the detected stent-struts;
• and
• the one or more indicators superimposed on the vessel image.