The goal of this study is to describe the techniques for coronary multi-slice CT angiography and to illustrate the spectrum of artifacts that can simulate coronary artery stenosis and lead to non-assessable segments using 128- and 160 multi-detector row CT scanners and discuss post-processing pitfalls with each. In addition, to review the normal anatomy and anatomic variants of the coronary arteries and discuss effective strategies for improving the diagnostic accuracy of coronary CT angiography.

Inclusion Criteria:

• Male and female patients of at least 18 years of age, with suspected symptomatic CAD.

Exclusion Criteria:

• Un cooperative patients.
• Those who have allergy to iodinated contrast material or contrast-induced nephropathy,
• Elevated serum creatinine level (1.5 mg/dl) or creatinine clearance >60 ml/min.
• Atrial fibrillation.
• Aortic stenosis.
• Percutaneous coronary intervention within the past 6 months.
• Intolerance to beta-blockers.
• Body mass index > 40
• Patients with Agatston calcium scores of >400