CORE-COMPARE Pilot Study

Inclusion Criteria: * Patients aged 21-85 years * Clinical history suggestive of CHD who are referred by their primary cardiologist for further evaluation via Computed tomography angiography (CTA) will be asked to participate. * Women of child bearing potential must demonstrate a negative pregnancy test within 24 hours of the study CTA. * Ability to understand and willingness to sign the Informed Consent Form. Exclusion Criteria: * Known allergy to iodinated contrast media. * History of multiple myeloma or previous organ transplantation * Elevated serum creatinine (\> 1.5mg/dl) OR calculated creatinine clearance of \< 60 ml/min (using the Cockcroft-Gault formula * Atrial fibrillation or uncontrolled tachyarrhythmia, or advanced atrioventricular block (second or third degree heart block) * Evidence of severe symptomatic heart failure (NYHA Class III or IV); * Known or suspected moderate or severe aortic stenosis * History of prior percutaneous coronary intervention (PCI) in one or more vessel or history of coronary arterial bypass grafting (CABG) * Suspected acute coronary syndrome * Presence of any other history or condition that the investigator feels would be problematic