Multislice CT angiography is a novel but already established and widely used in diagnosing coronary artery disease (CAD). It is very reliable in ruling out hemodynamically significant narrowings in coronary arteries (Negative predictive value). However, it may overestimate the severity of the stenoses in up to 30% of the coronary artery lesions (positive predictive value 70%). However, when coupled with a functional or flow-sensitive diagnostic test, such as PET perfusion or coronary doppler ultrasonography, one can assume that even the PPV may be as high as 95 %. Despite this assumption, there's no scientific evidence to support use of such hybrid multi-modality tests at present.

The investigators hypothesis is that improving the diagnostic accuracy of non-invasive diagnosis of coronary artery disease will decrease the proportion of patients that need catheter angiographies. The avoidance of these unnecessary invasive procedures will improve patients´ quality of life and may even redirect health care resources in a more efficient way.

Coronary MDCTA (multi-detector CT angiography) is a novel but already established and widespread diagnostic method to diagnose coronary artery disease. When performed with a 64-detector (slice) CT, its strength is an excellent negative predictive value, NPV (98%). Specificity (86%) is good but the positive predictive value (PPV) is only moderate (70%). This is due to the ability of MDCTA to detect even minor vessel wall changes before they are functionally significant, and the tendency of CT to overestimate the volume of dense calcifications. However, when coupled with a functional or flow-sensitive diagnostic test, such as PET perfusion or coronary doppler ultrasonography, one can assume that even the PPV may be as high as 95 %. Despite this assumption, there's no scientific evidence to support use of such hybrid multi-modality tests at present.

Our hypothesis is that improving the diagnostic accuracy of non-invasive diagnosis of coronary artery disease will decrease the proportion of patients that need catheter angiographies. The avoidance of these unnecessary invasive procedures will improve patients´ quality of life and may even redirect health care resources in a more efficient way.

Inclusion Criteria:

• informed consent
• age 40 - 80 years
• stable chest pain
• likelihood of obstructive coronary artery disease more than 25% based on gender, age, symptoms and exercise test

Exclusion Criteria:

• irregular rhythm
• hypersensitivity to contrast agents
• unstable chest pain
• decompensated congestive heart failure
• abnormal kidney function
• 2nd or 3rd degree AV block
• severe bronchial asthma
• pregnancy
• age over 80 years
• previously diagnosed coronary artery disease

Patients with chest pain