Contour extraction device, contour extraction method, and contour extraction program

A contour extraction method that is executed by a processor provided in a contour extraction device, the method comprising:

• propagating a contour of a region of interest of a first tomographic image in a three-dimensional image, which is formed of a plurality of tomographic images, each including the region of interest, in a first direction from the first tomographic image to a second tomographic image to extract first contours of the regions of interest of tomographic images between the first tomographic image and the second tomographic image, and propagating a contour of the region of interest of the second tomographic image in a second direction from the second tomographic image to the first tomographic image to extract second contours of the regions of interest of tomographic images between the first tomographic image and the second tomographic image, wherein the first direction is opposite to the second direction;
• and
• outputting a correction instruction for a contour in a third tomographic image between the first tomographic image and the second tomographic image in a case where a difference between the first contours and the second contours in the third tomographic image is a threshold value or more,
• in a case where the difference is the threshold value or more, extracting the first contours and the second contours using a contour corrected in accordance with the correction instruction as the contour of the region of interest of the second tomographic image, in a tomographic image group from the first tomographic image to the third tomographic image.

A non-transitory computer readable recording medium storing a contour extraction program for causing a processor provided in a contour extraction device to execute a process comprising:

• propagating a contour of a region of interest of a first tomographic image in a three-dimensional image, which is formed of a plurality of tomographic images, each including the region of interest, in a first direction from the first tomographic image to a second tomographic image to extract first contours of the regions of interest of tomographic images between the first tomographic image and the second tomographic image, and propagating a contour of the region of interest of the second tomographic image in a second direction from the second tomographic image to the first tomographic image to extract second contours of the regions of interest of tomographic images between the first tomographic image and the second tomographic image, wherein the first direction is opposite to the second direction;
• and
• outputting a correction instruction for a contour in a third tomographic image between the first tomographic image and the second tomographic image in a case where a difference between the first contours and the second contours in the third tomographic image is a threshold value or more,
• in a case where the difference is the threshold value or more, extracting the first contours and the second contours using a contour corrected in accordance with the correction instruction as the contour of the region of interest of the second tomographic image, in a tomographic image group from the first tomographic image to the third tomographic image.