A cardiac gated spiral CT scanner (10) has a source of penetrating radiation (20) arranged for rotation about an examination region (14) having a central axis extending in a z direction. The source (20) emits a beam of radiation (22) that passes through the examination region (14) as the source (20) rotates. A patient support (30) holds a patient within the examination region (14) and translates the patient through the examination region (14) in the z direction while this source (20) is rotated such that the source (20) follows a helical path relative to the patient. A control processor (90) implements a patient-specific scan protocol in response to measured patient characteristics (for example, the patient's heart rate, the patient's breath hold time, and/or the range of coverage in the z direction based on the patient's anatomy) and scanner characteristics (for example, the number of detector rings, and/or the scan rate). Radiation detectors (40) are arranged to receive radiation from the source (20) after it has traversed the examination region (14). An ECG monitor (80) acquires ECG data from the patient. The ECG data is used to correlate phases of the patient's heart with data collected by the radiation detectors (40). An image reconstruction processor (60) reconstructs image representations of the patient based on data received from the radiation detectors (40) and ECG monitor (80). A human viewable display (70) selectively displays the image representations for assessing cardiac function.