ASIR technique reduces already low radiation dose delivered during CTC by another 50%: Study

CTC can now use only one-quarter of the dose of an abdominal CT scan

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.

Performed at the Mayo Clinic in Scottsdale, AZ, the study included a colon phantom that was imaged at 50 mAs (approximately 5 mSv) and at 10-40 mAs (approximately 1-4 mSv) using six different ASIR levels and 18 patients that were scanned using a standard CTC dose of 50 mAs (approximately 5 mSv) and at a reduced dose of 25 mAS (approximately 2.5 mSv) using 40 percent ASIR. "In patients, no significant image quality differences were identified between standard- and low-dose images using ASIR," said Johnson. The phantom study showed image noise reduction that correlated with a higher percentage of ASIR.

"The results of this pilot study show that the radiation dose during CTC can be reduced 50 percent below currently accepted low-dose techniques without significantly affecting image quality when ASIR is used," said Johnson.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Muvalaplin shows promise in lowering Lp(a) levels in clinical trial