Abstract
Recent technological advances in MDCT enabled the introduction of the noninvasive technique for the routine workup of the coronary arteries in daily clinical practice. Patients with a low to intermediate likelihood of coronary artery disease (CAD) and having equivocal findings at electrocardiogram (ECG) or stress tests are the optimal candidates to undergo noninvasive coronary imaging with CT. In order to gain high diagnostic accuracy, the CT scanner system should provide high temporal and spatial resolutions. This is necessary to compensate for motion of the coronary arteries and to allow for multiplanar reformations without artifacts. The CT data need to be synchronized to the simultaneously recorded ECG, and both retrospective ECG gating or prospective ECG triggering can be used for data acquisition and reconstruction. When implementing the technique of ECG pulsing for reducing the radiation dose, flexible adjustments of the pulsing widths at different heart rates are recommended. With regard to the image quality, the dependency on the average heart rate and variability decreases with the increasing temporal resolution of the CT system. When using 64-slice CT, average heart rate and heart rate variability should be diminished through the foregoing administration of β-blockers. With dual-source CT, a reduction of heart rate and variability is no longer necessary. Severe arterial wall calcification still hamper the diagnostic capabilities of CT, even when using the most recent technology. With every new CT scanner generation, the robustness increases, while the rate of nondiagnostic coronary artery segments decreases.
Alkadhi, H