Dynamic analysis apparatus, dynamic analysis system, expected rate calculation method, and recording medium

1. A dynamic analysis apparatus that predicts a respiratory function value of a subject based on a plurality of frame images showing dynamics of a chest of the subject, the dynamic analysis apparatus comprising: a hardware processor that:

obtains a first lung size value of a removal target site and a second lung size value of a left or right lung field that includes the removal target site, in lung fields of the subject;

calculates a proportion between the first lung size value of the removal target site and the second lung size value of the left or right lung field that includes the removal target site, as a size proportion;

calculates a first feature amount concerning respiratory function of the left or right lung field that includes the removal target site and a second feature amount concerning respiratory function of the lung fields as a whole, based on the plurality of frame images;

calculates a proportion between the first feature amount concerning the respiratory function of the left or right lung field that includes the removal target site and the second feature amount concerning the respiratory function of the lung fields as a whole, as a feature amount proportion; and

calculates an expected rate of the respiratory function after the removal target site is removed from the lung fields, based on a product of the calculated size proportion and the calculated feature amount proportion.

2. The dynamic analysis apparatus according to claim 1 , wherein the hardware processor:

obtains information on an anatomical unit corresponding to the removal target site; and

obtains, from a memory in which lung size values of anatomical units of lungs are stored, a lung size value of the anatomical unit corresponding to the removal target site and a lung size value of an anatomical unit corresponding to the left or right lung field that includes the removal target site.

3. The dynamic analysis apparatus according to claim 2 , wherein each anatomical unit is any one of a left or right lung, a lobe, a pulmonary segment, and a pulmonary subsegment.

4. The dynamic analysis apparatus according to claim 1 , wherein the hardware processor:

obtains a respiratory function value of the lung fields as a whole of the subject; and

multiplies the obtained respiratory function value by the expected rate to obtain an expected respiratory function value after the removal target site is removed from the lung fields.

5. The dynamic analysis apparatus according to claim 1 ,

wherein the plurality of frame images is images that are captured before lung surgery,

wherein the removal target site is a target site to be removed in the lung surgery.

6. The dynamic analysis apparatus according to claim 1 , wherein the first feature amount and the second feature amount are feature amounts of ventilation, feature amounts of pulmonary blood flow function, or feature amounts calculated respectively based on the feature amounts of ventilation and the feature amounts of pulmonary blood flow function.

7. The dynamic analysis apparatus according to claim 1 , wherein the hardware processor:

extracts left and right lung field regions from the plurality of frame images; and

calculates the first feature amount concerning the respiratory function of the left or right lung field that includes the removal target site and the second feature amount concerning the respiratory function of the lung fields as a whole, based on the left and right lung field regions extracted from the plurality of frame images.

8. A dynamic analysis system comprising:

the dynamic analysis apparatus according to claim 1 ; and

an imaging apparatus that performs radiographic imaging of the subject to obtain the plurality of frame images showing dynamics of the chest of the subject.

9. An expected rate calculation method for a dynamic analysis apparatus that predicts a respiratory function value of a subject based on a plurality of frame images showing dynamics of a chest of the subject, the method comprising:

obtaining a first lung size value of a removal target site and a second lung size value of a left or right lung field that includes the removal target site, in lung fields of the subject;

calculating a proportion between the first lung size value of the removal target site and the second lung size value of the left or right lung field that includes the removal target site, as a size proportion;

calculating a first feature amount concerning respiratory function of the left or right lung field that includes the removal target site and a second feature amount concerning respiratory function of the lung fields as a whole, based on the plurality of frame images;

calculating a proportion between the first feature amount concerning the respiratory function of the left or right lung field that includes the removal target site and the second feature amount concerning the respiratory function of the lung fields as a whole, as a feature amount proportion; and

calculating an expected rate of the respiratory function after the removal target site is removed from the lung fields, based on a product of the calculated size proportion and the calculated feature amount proportion.

10. A non-transitory recording medium storing a computer-readable program that causes a computer used for a dynamic analysis apparatus that predicts a respiratory function value of a subject based on a plurality of frame images showing dynamics of a chest of the subject:

to obtain a first lung size value of a removal target site and a second lung size value of a left or right lung field that includes the removal target site, in lung fields of the subject;

to calculate a proportion between the first lung size value of the removal target site and the second lung size value of the left or right lung field that includes the removal target site, as a size proportion;

to calculate a first feature amount concerning respiratory function of the left or right lung field that includes the removal target site and a second feature amount concerning respiratory function of the lung fields as a whole, based on the plurality of frame images;

to calculate a proportion between the first feature amount concerning the respiratory function of the left or right lung field that includes the removal target site and the second feature amount concerning the respiratory function of the lung fields as a whole, as a feature amount proportion; and

to calculate an expected rate of the respiratory function after the removal target site is removed from the lung fields, based on a product of the calculated size proportion and the calculated feature amount proportion.