X-ray computerized tomography apparatus, breathing indication apparatus and medical imaging apparatus

An X-ray computed tomographic apparatus comprising:

• a gantry including an X-ray tube which generates X-rays and an X-ray detector which detects X-rays transmitted through a subject to be examined;
• a tomogram generating unit which generates tomogram data on the basis of an output from the X-ray detector;
• a cardiac index calculating unit which instantly calculates a plurality of cardiac indexes associated with a heartbeat state on the basis of an electrocardiogram associated with the subject;
• a cardiac index selection unit which selects at least one cardiac index among the plurality of calculated cardiac indexes in accordance with a user instruction;
• and
• a display unit which is held on a housing of the gantry directly or through an arm and instantly displays the selected cardiac index.