Examination support device, examination support method, and examination support program

1. An examination support device comprising:

an image acquisition unit that acquires a first medical image in a first expression form and a second medical image in a second expression form different from the first expression form;

a conversion unit that acquires a converted first medical image and a converted second medical image by converting the first expression form of the first medical image and the second expression form of the second medical image into a third expression form; and

a similarity calculation unit that calculates similarity between the converted first medical image and the converted second medical image.

2. The examination support device according to claim 1 ,

wherein the first medical image is an actual image acquired by imaging a subject, and the second medical image is an image generated from an image acquired by imaging the subject through a method different from that of the actual image.

3. The examination support device according to claim 2 ,

wherein the first medical image is an actual endoscopic image which is generated using an endoscope inserted into a tubular structure of the subject and represents an inner wall of the tubular structure,

wherein the second medical image is a virtual endoscopic image which is generated from a three-dimensional image including the tubular structure of the subject and spuriously represents the inner wall of the tubular structure,

wherein the converted first medical image is a first depth image representing a distance to the inner wall of the tubular structure from a viewpoint of the first medical image, and

wherein the converted second medical image is a second depth image representing a distance to the inner wall of the tubular structure from a viewpoint of the second medical image.

4. The examination support device according to claim 3 , further comprising:

a position estimation unit that estimates a position of the endoscope in the tubular structure using the virtual endoscopic image of which the calculated similarity is greater than or equal to a predetermined threshold value.

5. The examination support device according to claim 4 ,

wherein the position estimation unit estimates the position of the endoscope in the tubular structure based on the difference in pixel values between the first depth image and the second depth image.

6. The examination support device according to claim 4 , further comprising:

a display control unit that displays the first depth image and the second depth image corresponding to the estimated position of the endoscope on a display unit.

7. The examination support device according to claim 3 , further comprising:

a virtual endoscopic image generation unit generating the virtual endoscopic image from the three-dimensional image.

8. An examination support method comprising:

acquiring a first medical image in a first expression form and a second medical image in a second expression form different from the first expression form;

acquiring a converted first medical image and a converted second medical image by converting the first expression form of the first medical image and the second expression form of the second medical image into a third expression form; and

calculating similarity between the converted first medical image and the converted second medical image.

9. A non-transitory computer-readable storage medium that stores an examination support program causing a computer to execute:

a step of acquiring a first medical image in a first expression form and a second medical image in a second expression form different from the first expression form;

a step of acquiring a converted first medical image and a converted second medical image by converting the first expression form of the first medical image and the second expression form of the second medical image into a third expression form; and

a step of calculating similarity between the converted first medical image and the converted second medical image.