الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
In the fall of 1998, four of the largest CT vendors launched what commonly came to be called multi-row detector CT. We are currently in a very active developmental phase of this technology(1). The introduction of this new CT technique was as revolutionary for the field of radiology as the original introduction of CT in 1972 and the introduction of helical CT in 1989. Already in 1992 dual-channel CT was introduced. The dual-channel CT scanners did not get the same attention as the four-channel scanners got 6 years later. One of the cornerstones of multi-row detector CT is a very fast image-acquisition phase. Total body scanning times have been reduced to less than 30 seconds(10). This speed is beneficial when large segments of the body have to be scanned or image acquisition has to be fast to catch a dynamic event, such as brain perfusion or CT angiography. Alternatively, the MDCT can be used to produce high milliamperes, which allows scanning through dense areas, such as shoulders or orthopedic hardware. In addition to short acquisition times and high milliamperes, MDCT allows scanning with submillimeter section thickness, which creates ultra high-resolution images(9,10).
Multi-Row Detector CT has a multiple rows of detectors which allow for registration of more than one channel per gantry rotation. If the detector row array is equipped with the capacity to collect four simultaneous channels of information during each gantry rotation, the scanner is called a four-channel scanner. It has a fourfold capacity to register slices during each gantry rotation. If the number of simultaneous registered channels is increased to 8 or 16 by adding more electronics to the detector system, the capacity to register slices increases similarly. A scanner’s number of channels and the gantry rotation time determine the number of slices that can be acquired per unit time. For example, a single-channel scanner with a gantry rotation time of 1 second can acquire one slice per second, whereas a 16-channel scanner with 0.4-second rotation time can acquire up to 38 slices per second (Table 1) (9).