CROSS-REFERENCE TO RELATED APPLICATIONS

The entire disclosure of Japanese Patent Application No. 2019-029110 filed on Feb. 21, 2019 is incorporated herein by reference in its entirety.

BACKGROUND

Technological Field

The present disclosure relates to an image processing apparatus and a storage medium.

Description of the Related Art

An equation for estimating exposure doses of patients with which exposure doses (entrance surface doses) of patients can be easily obtained in any medical facility is disclosed in the following literature: Hiroki SHIMAZAKI and seven other persons, “Estimated equation of Patient dose in Diagnostic radiology”,Japanese journal of Medical Physics, vol. 19, no. 4, pp. 209-217. The equation for estimating exposure doses of patients has been made by adding a correction factor to an approximate equation that expresses X-ray output of X-ray apparatuses.

SUMMARY

However, the abovementioned equation for estimating exposure doses of patients uses fixed values as values of the body thickness and the irradiation field size that are necessary for determining a backscatter factor. Hence, accuracy of exposure doses of patients calculated by the above equation is low.

The present invention has been conceived in view of the above problems, and objects thereof include providing an image processing apparatus and a storage medium for easily and accurately calculating exposure doses of subjects.

In order to achieve at least one of the abovementioned objects, according to a first aspect of the present invention, there is provided an image processing apparatus including a hardware processor that:

estimates a body thickness and an irradiation field region of a subject based on a radiograph obtained by radiographing the subject;

calculates a distance from a focus of a radiation source to a radiation entrance point based on the estimated body thickness;

calculates an irradiation field size based on the estimated irradiation field region; and

calculates an exposure dose based on the calculated distance, the calculated irradiation field size, and an imaging condition used in radiographing the subject,

According to a second aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program that causes a computer to:

estimate a body thickness and an irradiation field region of a subject based on a radiograph obtained by radiographing the subject;

calculate a distance from a focus of a radiation source to a radiation entrance point based on the estimated body thickness;

calculate an irradiation field size based on the estimated irradiation field region; and

calculate an exposure dose based on the calculated distance, the calculated irradiation field size, and an imaging condition used in radiographing the subject.

