X-ray CT imaging apparatus and method of controlling X-ray CT imaging apparatus

An X-ray CT imaging apparatus comprising:

• a supporter that supports an X-ray generator and an X-ray detector such that the X-ray generator and the X-ray detector are opposed to each other with a subject sandwiched therebetween;
• motors configured to turn the supporter including
• a first motor that turns the supporter about a shaft having an axis located between the X-ray generator and the X-ray detector, the axis located closer to the X-ray detector than a center position between the X-ray generator and the X-ray detector, and
• a second motor that moves the shaft in a direction intersecting with an axial direction of the shaft;
• and
• a processor that receives a setting of a position of an X-ray CT imaging region with respect to a local part of a dental arch of a head of the subject and controls the first motor and the second motor, wherein
• the processor allows the second motor to move the shaft in synchronization with turning of the supporter about the shaft using the first motor, and the supporter is caused to perform combined motion, whereby the X-ray generator and the X-ray detector turn about the X-ray CT imaging region,
• a position of the shaft is controlled according to the set position of the X-ray CT imaging region, and
• a first distance between the X-ray CT imaging region and the X-ray detector when the X-ray detector passes through a trajectory behind a back of the head during performance of X-ray CT imaging on a molar tooth of the dental arch is smaller than a second distance between the X-ray CT imaging region and the X-ray detector when the X-ray detector passes through a trajectory behind the back of the head during performance of X-ray CT imaging on a front tooth of the dental arch.