[Current indications for cardiac CT]

There is a need to define the current indications for coronary CT angiography (CCTA) even as technology continuously evolves. CCTA using 64 MDCT units has shown to be highly accurate for diagnosis of stenoses >or=50% on selected populations. It is currently used for its negative predictive value (96-98%). Stenosis quantification remains inferior to conventional coronary angiography with tendency to overestimate stenoses <70%. For diagnosis of coronary artery disease, CCTA is considered based on clinical findings (pre-test probability of coronary artery disease) and presence of myocardial ischemia on other functional studies. The main appropriate indications include: In the setting of acute coronary syndrome, CCTA excludes coronary artery disease with excellent NPV and good negative likelihood ratio (0.05) when ECG is non-contributory, 2 consecutive troponin levels at 6 hours are negative in a patient with low risk of coronary artery disease. In the setting of stable angina or atypical precordial chest pain, CCTA is indicated in patient with low to medium risk when functional test are non-contributory or unavailable, or ECG is non-interpretable. CCTA is a complement to coronary angiography for morphological evaluation of some lesions prior to angioplasty and stent placement (long segment occlusion, proximal lesions involving LAD and circumflex arteries). In selected patients, CCTA may replace coronary angiography prior to valvular surgery.