Cardiac phase selection method and medical imaging method

A medical imaging method, comprising:

• obtaining a coronary image quality score curve of a subject under examination, wherein the coronary image quality score curve is used to quantitatively characterize the medical image quality of a coronary medical image dataset of the subject under examination at a plurality of cardiac phases;
• determining a phase corresponding to a peak point in the coronary image quality score curve as a first cardiac phase, wherein a motion amplitude of the heart of the subject under examination at the first cardiac phase is less than a motion amplitude thereof at an adjacent phase, and the first cardiac phase is within one of a systolic range and a diastolic range;
• determining a phase corresponding to another peak point in the coronary image quality score curve as a second cardiac phase, wherein a motion amplitude of the heart of the subject under examination at the second cardiac phase is less than a motion amplitude thereof at an adjacent phase, and the second cardiac phase is within the other of the systolic range and the diastolic range;
• and
• obtaining coronary medical images at the first cardiac phase and the second cardiac phase.