Coronary angiography is capable to visualize even smallest lumen alterations due to its high temporal and spatial resolution. However it does not deliver any information about the coronary wall morphology. Contrary to coronary CT angiography the diagnostic accuracy of coronary angiography is not limited by heart rate and rhythm or severe calcifications. The fact that in the case of a significant coronary stenosis, immediate therapy can be done is a big advantage.
Coronary Angiography

Coronary CT Angiography Coronary CT angiography (CTA) is a useful diagnostic method in specific clinical situations, especially in acute patients with inconclusive results from ECG and lab testing (Appropriateness Criteria for Cardiac CT and Cardiac MRI¹). The diagnostic accuracy of coronary CTA relates to the detection of significant coronary artery stenosis (> 50%), diagnosed by invasive coronary angiography. Coronary CTA has a high negative predictive value (NPV) and therefore is especially useful for exclusion of significant coronary artery stenosis with a sensitivity between 83 and 99% and a specificity of 81 to 96% ^2,3. In several studies it could be demonstrated, that inclusion of cardiac CT not only improves quality of care for acute chest pain patients, but may also save money, e.g. due to the fact of being able to spare beta blockers for lowering the heart rate. ⁴ Recent studies could demonstrate, that DSCT may overcome all of the above mentioned limitations of coronary CTA ⁵, DSCT allows not only the evaluation of native coronary arteries, but also of stents and bypass grafts. DSCT looks also very promising for diagnosis of transplant vasculopathy in patients after heart transplantation, who demonstrate high heart rates ⁶. 
Cardiovascular CT
Case Study: Thrombosed Aortocoronary Venous Bypass Graft

Coronary MR Angiography (MRA) is another technique that can be used for the diagnostic evaluation of the coronary arteries. According to the Appropriateness Criteria (Appropriateness Criteria for Cardiac CT and Cardiac MRI¹) CMR is indicated for evaluation of coronary anomalies. The reported diagnostic accuracy to detect significant stenoses depends on the diameter of the evaluated vessels: accordingly, the sensitivity for MRA is 72-93% and the specificity 42-90%. Higher diagnostic accuracy can be achieved usually by higher spatial resolution as provided by cardiac CT and invasive angiography. Although MRA is not the method of choice for routine stenosis evaluation, it can achieve better diagnostic performance compared to other non-invasive tests in patients with high coronary calcification.⁷ New non-invasive coronary MRA techniques, such as the 3D Whole-Heart MRA, enable a CT-like easy exam planning. 3D datasets can be reformatted in all planes and volume rendered images (VRT) can be created in a similar fashion. In a free-breathing acquisition, a 3D coronary MRA can be performed in less than 10 minutes. With motion adaptive respiratory gating, even diaphragm shifts can be compensated. 
Cardiovascular MR