Step-and-shoot cardiac CT imaging

A method of CT imaging, the method comprising:

• attaching an ECG monitor to a scan subject, the ECG monitor configured to acquire cardiac motion data from the subject;
• rotating an x-ray source through a series of projection angles and at a rotational speed about the scan subject along an annular path of rotation when the scan subject is positioned at a discrete scan position;
• acquiring a first set of gated cardiac imaging data;
• adjusting a spacing of a pre-patient collimator based on data acquired in the ECG monitor;
• assessing from ECG data acquired whether a cardiac irregularity occurred during the acquisition of the first set of imaging data;
• and
• acquiring a second set of gated cardiac imaging data at the discrete scan position if the assessment indicates an irregularity occurred during acquisition of the first set of data.