Cardiac multidetector computed tomography: where do we stand?

Multidetector-row CT (MDCT) scanners for the noninvasive detection of coronary artery disease (CAD) were introduced in 1999, with the 4-slice scanners that allowed small and rapidly moving structures like the coronary arteries to be visualized with sufficient image quality. Soon, the technology advanced further, with the introduction of 16-, 40-, and 64-slice scanners (current systems) and prototype 256and 320-detectorCT. The new generation of 64 MDCT scanners permitted greater patient coverage per gantry rotation and thus a shorter scan time. Breath-hold time with the current 64-slice scanners is 5-10 s, resulting in less patient discomfort and fewer artifacts induced by respiratory motion or heart rate variability. The shorter acquisition time allows the use of smaller volumes of intravenous contrast material (90-100 ml) and reduces radiation exposure. Recently, dual-source MDCT scanners were launched, having two pairs of X-ray sources and multislice detectors mounted at 90Æ to each other. This technology alCardiac Multidetector Computed Tomography: Where Do We Stand?