Reducing Tube Current to Manage CT Radiation Dose

Published on the Aug. 8, 2011, DiagnosticImaging.com Web site

By Whitney L.J. Howell

Using lower fixed-tube current or automatic exposure control techniques when performing adult and pediatric head CT scans can reduce radiation dose and ease concern about cancer risk, according to a recent study published in the Journal of the American College of Radiology.

Head CTs account for 28 percent of all CT scans performed annually nationwide, but there is still a lack of data about the long-term effects of the radiation associated with them. This uncertainty makes it your responsibility to limit the amount of radiation you use to only what is absolutely necessary, said Mahadevappa Mahesh, PhD, associate professor of radiology and cardiology at Johns Hopkins Hospital.

“Across the board, there’s no uniform protocol for head CTs or perfusion head CTs,” said Mahesh, the study’s lead author. “Controlling tube current is the most straight forward way to manage radiation because it has a linear relationship with the amount of radiation you use.”

For example, previous research from the American Journal of Neuroradiology found a radiation dose reduction of 47 percent accompanied a 50 percent cut in tube current. Image quality at this dosage is relatively unchanged.

To read the remainder of the article: http://www.diagnosticimaging.com/low-dose/content/article/113619/1923193