This study is intended to collect clinical feasibility data using this prototype research mode for the purposes of understanding potential clinical impact, potential limitations and strengths, and to further develop the technique through development of image reconstruction and processing approaches or identification of other areas of development required.

Up to 38 subjects may be enrolled to achieve the target number of 30 evaluable subjects. Withdrawn or discontinued subjects who are enrolled and received the investigational scan, may be replaced. Subject participation will be deemed complete once the diagnostic and investigational scans are completed. A subject is considered evaluable when images and raw data from the diagnostic single energy cardiac CT scan and raw data from the investigational dual energy cardiac CT scan have been collected successfully and demonstrate a diagnostic interpretation.

Inclusion Criteria:

1. Patients > 50 years old undergoing routine cardiac CT imaging exam;
2. Patients that within last 12 months did not undergo medical procedures involving ionizing radiation;
3. Signed informed consent.

Exclusion Criteria:

1. Contradictions to contrast;
2. Contraindications for beta blocker;
3. BMI >30;
4. High heart rate ≥75 BPM;
5. Atrial Fibrillation;
6. Arrythmia or irregular heartbeats;
7. Pregnant women;
8. Patients lacking capacity in providing informed consent
9. Patients who did participate in prior research studies with ionizing radiation in the last 12 months.

Subjects will be enrolled that will be undergoing a routine cardiac CT imaging scan. Subjects will be representative of the general population expected to undergo cardiac CT imaging as standard of care clinical practice.