Considerable Reductions’ in Radiation Exposure Possible with 16-MDCT Scanner on Body Applications

By using a 16-slice scanner as opposed to a 4-slice scanner, considerable reductions in effective radiation dose can be achieved on body CT without sacrificing established clinical image quality levels, a new study by researchers from Leiden University Medical Center in Leiden, The Netherlands, says.

Specifically, the authors state that by using carefully optimized volumetric imaging protocols with 16-MDCT (multidetector computed tomography), a dose reduction of 20–30% can be achieved in standard protocols on normal-sized patients, even without the incorporation of automatic exposure control software. “Much of this is due to the better geometric and detector efficiency of the 16-slice CT units, which is expected to continue with the further improvement in efficiency with the coming 32 to 64–slice units,” said Aart J. van der Molen, MD, lead author of the study.

In fact, according to Dr. van der Molen, not only can lower radiation doses be achieved with 16-MDCT, the imaging itself can even be improved at that lower radiation level. “With 16-MDCT, one can trade through-plane resolution for noise (scan thin, view thicker). This is often not optimally possible using 4-MDCT because of the long breath-holds and low geometric efficiency at very thin slices. So the overall clinical imaging quality, especially when taking the coronal and sagittal orientations into account, can be improved with a 16-slice CT scanner at a reduced dose level,” he said.

According to the authors, their findings do not completely rule out the use of 4-MDCT for body applications, but they do recommended 16-MDCT for body CT in the most important regions (chest, abdomen and pelvis), if the technology is at hand. “In hospitals that have both technologies available, this opens up the possibility to scan patient groups that have a higher risk for detrimental effects of radiation, such as children, with the most dose-efficient equipment available,” said Dr. van der Molen.

Dr. van der Molen will present the study on May 3 during the American Roentgen Ray Society Annual Meeting in Miami Beach, FL.