[How I investigate... The coronary arteries in 2007: contributions of CT coronary angiography]. / Comment j'explore...Les artères coronaires en 2007: apports de la tomodensitomètrie.

ABSTRACT

Cardiac imaging has always been a challenge because of the continuous movement of the heart. Cardiac computed tomography (CT) has undergone an accelerated progression over the past decade, due to the combination of the high-speed rotation of the X-ray tube, the ECG-gating technique and the infra-millimeter spatial resolution. Multidetector CT allows visualisation of the coronary artery lumen and the detection of coronary stenosis after intravenous injection of contrast medium. Studies have demonstrated a high negative predictive value of CT coronary angiography (CTCA). CTCA may be reasonably used for the assessment of symptomatic patients, especially in the setting of equivocal treadmill or functional testing. Also, CTCA allows assessment of coronary bypass graft patency and recognition of aberrant coronary arteries. Limitations in the use of this technique exist atrial fibrillation and other cardiac arrhythmias remain a contraindication; severe calcifications are the most frequent reason for impaired assessment of coronary arteries. High radiation doses prohibit the use of this test as a screening tool for asymptomatic patients.