Featured Research

from universities, journals, and other organizations

Latest findings in CT radiation dose reduction efforts

Date:
August 4, 2010
Source:
Mayo Clinic
Summary:
In recent years, advances in CT scanner technology have made perfusion computed tomography imaging an important diagnostic tool for patients with suspected stroke. Now, researchers are working to reduce radiation dosages used to acquire perfusion and other CT images.

In recent years, advances in CT scanner technology have made perfusion computed tomography (CT) imaging an important diagnostic tool for patients with suspected stroke. Now, researchers at Mayo Clinic are working to reduce radiation dosages used to acquire perfusion and other CT images.

Mayo Clinic medical physicist Cynthia McCollough, Ph.D., and her group of researchers presented their findings related to CT dose reduction at the 52nd Annual Meeting of the American Association of Physicists in Medicine on July 20 in Philadelphia. The presentation was entitled "20-Fold Dose Reduction Using a Gradient Adaptive Bilateral Filter: Demonstration Using in Vivo Animal Perfusion CT."

"We believe in the clinical value of perfusion CT, and though there is no documented risk of injury at the currently prescribed radiation levels, we are trying to lower the dose for the benefit of patients," says Dr. McCollough, diagnostic radiologist, Mayo Clinic.

The As Low As Reasonably Achievable, or ALARA, principle has always guided Mayo Clinic's approach to the dosages of radiation used to acquire CT images. Dr. McCollough's team has been experimenting with a newly created image-processing algorithm that produces high-quality perfusion CTs with up to 20 times less the radiation used under existing protocols. Depending on the diagnostic application, a perfusion CT exam takes about 30 seconds to scan the tissue multiple times after iodine has been injected. This technique detects changes in blood volume and flow that reveal injuries to vessels or a tumor's response to treatment. Information from each consecutive scan is then digitally cross-referenced with other images taken during the exam to improve image quality and reduce distortions.

Thus far, the new perfusion CT algorithms have proved effective in animal models, and Dr. McCollough's team has begun looking at ways to introduce the methodologies into clinical practice.

"When we use very low doses of radiation to acquire a CT, image graininess can significantly decrease the value of the exam," says the study's first author, Juan Carlos Ramirez Giraldo, Mayo Clinic. "With this new algorithm, we are able to maintain the image quality by cross-referencing it with other images collected during the exam."

In related efforts, using one of the latest CT scanners on the market, Mayo Clinic already has other advanced algorithms as part of its clinical practice. A team of radiologists and physicists have recently implemented a new routine head CT protocol that cuts radiation dose by nearly 50 percent. While the American College of Radiology allows its accredited facilities to use head CT doses up to approximately 75 mGy, Mayo Clinic's newly introduced patient protocol uses a dose of only 38 mGy. This dose reduction is particularly significant as head CT exams are one of the most commonly performed CT procedures.

When asked how the new head CT protocol is changing clinical practice, neuroradiologist David DeLone, M.D., Mayo Clinic, says, "patients aren't aware that anything has changed, and as radiologists looking at a study, we don't know anything has changed. Yet, we are obtaining high-quality images, more consistently and in shorter times, while exposing patients to about half of the radiation dose. It's a win-win for everyone."


Story Source:

The above story is based on materials provided by Mayo Clinic. Note: Materials may be edited for content and length.


Cite This Page:

Mayo Clinic. "Latest findings in CT radiation dose reduction efforts." ScienceDaily. ScienceDaily, 4 August 2010. <www.sciencedaily.com/releases/2010/08/100803152821.htm>.
Mayo Clinic. (2010, August 4). Latest findings in CT radiation dose reduction efforts. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2010/08/100803152821.htm
Mayo Clinic. "Latest findings in CT radiation dose reduction efforts." ScienceDaily. www.sciencedaily.com/releases/2010/08/100803152821.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins