6.23.2010

ASIR Technique Significantly Reduces Already Low Radiation Dose from CT Colonography

A newly adapted low-dose computed tomography (CT) technique called adaptive statistical iterative reconstruction (ASIR) can help radiologists reduce the already low radiation dose delivered during CT colonography (CTC) by another 50 percent, according to a study published in the July issue of the American Journal of Roentgenology (www.ajronline.org).

ASIR is a technique that allows radiologists to reduce the noise in an image and improve image quality (like adjusting a TV antenna to make a “fuzz” image sharper) while reducing the radiation dose to only one-quarter of that delivered by a typical abdominal CT scan.

“Despite the fact that the radiation dose delivered by CTC was already low and a lack of conclusive data regarding risk from medical radiation, radiologists strive to reduce dose at every opportunity,” said C. Daniel Johnson, MD, lead author of the study. “This new technique allows us to use far less radiation than even a typical abdominal CT scan without compromising image quality. CTC has been shown to be an effective front line screening tool for colorectal cancer. The fact that we can now screen patients with an increasingly lower dose can allay concerns, attract more patients to be screened and ultimately save tens of thousands of lives each year,” said Johnson.

source: ARRS