01 YIAMDCT Ch 1 pp. 1-4

Multidetector (MD) technology has created new dimensions in spatial and temporal resolution in computed tomography (CT) scanning. Multislice CT scanners allow non-invasive coronary angiography within a single breath hold by use of faster gantry rotation times and sophisticated algorithms for retrospective electrocardiographic gating 1 . Four-row CT scanners have shown promising results 2 , even with a scan time of approximately 40 s and suboptimal spatial and temporal resolution. Owing to the increased number of detector rows and faster gantry rotation, the introduction of 16-row scanners has decreased the time needed for imaging the entire heart to approximately 20 s and, thus, enabled consistent images of the coronary arteries to be obtained at CT angiography. An improved sensitivity of this technique in the detection of significant coronary artery stenoses has been reported 3,4 . A prerequisite for successful CT angiography is prominent vascular enhancement. In order to achieve this, the injection parameters must be accurately chosen and associated with synchronization protocols between the arterial passage of the contrast agent and CT data acquisition. The introduction of MD row CT technology requires even further optimization and synchronization, due to the shorter acquisition times 5 . Contrast enhancement in coronary CT angiography