Similarity determination apparatus, similarity determination method, and similarity determination program

A similarity determination method that determines a similarity between a first three-dimensional medical image and a second three-dimensional medical image, the similarity determination method comprising:

• displaying a tomographic image of a specific tomographic plane in the first medical image on a display;
• classifying each pixel of a partial region including at least the specific tomographic plane in the first medical image into at least one of a plurality of types of findings;
• calculating a first feature amount for each finding classified in the partial region;
• setting a weighting coefficient indicating a degree of weighting, which varies depending on a size of each finding, for each finding classified in the partial region;
• and
• performing a weighting operation for the first feature amount for each finding calculated in the partial region and a second feature amount for each finding calculated in the second medical image on the basis of the weighting coefficient to derive the similarity between the first medical image and the second medical image.

A non-transitory computer-readable storage medium that stores a similarity determination program that causes a computer to perform a process of determining a similarity between a first three-dimensional medical image and a second three-dimensional medical image, the similarity determination program causing the computer to perform:

• a step of displaying a tomographic image of a specific tomographic plane in the first medical image on a display;
• a step of classifying each pixel of a partial region including at least the specific tomographic plane in the first medical image into at least one of a plurality of types of findings;
• a step of calculating a first feature amount for each finding classified in the partial region;
• a step of setting a weighting coefficient indicating a degree of weighting, which varies depending on a size of each finding, for each finding classified in the partial region;
• and
• a step of performing a weighting operation for the first feature amount for each finding calculated in the partial region and a second feature amount for each finding calculated in the second medical image on the basis of the weighting coefficient to derive the similarity between the first medical image and the second medical image.