A Trial Comparing the Sensitivity and Specificity of Coronary Angiography With Coronary CT Angiography

40 Patients who are scheduled to undergo coronary angiogram will be recruited at Mount Scopus and Ein Kerem. Patients will be excluded if they have one or more of the following conditions

1. CABG or stent implantation in the past.

2. Atrial fibrillation

3. Contraindication for beta blockers

4. Obstructive pulmonary disease

5. Severe peripheral vascular disease

6. Sick sinus syndrome or AV block greater than 1st degree.

7. Systolic blood pressure below 100 mm Hg.

8. Renal disease or other conditions that might increase the risk of contrast nephropathy (diabetes mellitus, SLE, paraproteinemia, malignancy, liver disease)

9. Allergy to contrast material.

Coronary CT angiography: Patient preparation and data acquisition Pre-procedure preparation: Following informed consent, patients will be scheduled to undergo coronary CT angiography within 7 days prior to coronary angiogram. Patients with heart rates above 75 BPM's will be given 25 mg of metoprolol P.O. 60-90 minutes before the test. If the patient does not reach heart rate below 75, administration of additional IV metoprolol may be considered by a cardiologist.

Scanning protocol: Images will be obtained using collimation of 16x0.75 mm, slice thickness 1 mm reconstructed at increments of 0.5 mm, rotation time 0.42 seconds, kVp 140 and mAs 400. Prior to scanning, 120-150cc of non-ionic contrast material will be injected to a peripheral vein at a rate of 4-5mm/sec. Images will be obtained with ECG gating.