New Technology Reduces CT Radiation Dose

The control, called Real EC, was developed by Toshiba Medical Systems (Tokyo, Japan).

Real EC uses the detector signal recorded during the scanogram, which represents the average attenuation along the patient's body. A graph of this attenuation profile is displayed on the monitor. The data in the attenuation profile is used to modify the x-ray tube current as the helical image data is acquired to keep the image noise constant. Varying the tube current according to patient attenuation can allow for significant dose reduction, as much as 40% in some cases. Actual dose reduction depends on the individual patient and the anatomical region scanned.

Real EC is available on Toshiba's high-speed Aquilion and Asteion CT scanners. The control is applicable to all parts of the body and should be of particular benefit in pediatric exams. Operator options are provided that give fine control over the image quality and dose balance.

"For many years, film/screen radiology has been able to use automatic exposure control effectively, but attempts to extend this to CT have been cumbersome and not very useful until now,” said Joseph Fritz, senior clinical manager, Toshiba American Medical Systems.