ASIR technique significantly reduces radiation dose associated with abdominal CT scans

A new low-dose abdominal computed tomography (CT) technique called adaptive statistical iterative reconstruction (ASIR) can reduce the radiation dose associated with abdominal CT scans by 23-66 percent, according to a study in the September issue of the American Journal of Roentgenology. Abdominal CT scans are typically used to help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, bowel, and colon.

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 "fuzzy" image sharper) while reducing the radiation dose.

The study, performed at the Mayo Clinic in Scottsdale, AZ, included 53 patients who underwent contrast-enhanced abdominal low-dose CT with 40 percent ASIR. All 53 patients had previously undergone contrast-enhanced routine-dose CT with filtered back projection (FBP). The average dose reduction using the ASIR technique (compared to routine-dose CT with FBP) was 66 percent for patients with a body mass index (BMI) of less than 20 and 23 percent for patients with a BMI of 25 or greater. "A significant difference," said Amy K. Hara, MD, lead author of the study.

"The results of this study show that low-dose abdominal CT with ASIR is a viable technique with image quality that is nearly comparable to that of our routine dose techniques and is worthy of further study," said Hara.