ASIR Technique Can Reduce Radiation Dose from CT Colonography

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A new low-dose 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 in the July issue of the American Journal of Roentgenology.

ASIR allows radiologists to reduce the noise in an image and improve quality, similar to adjusting a television antenna to sharpen a fuzzy image, while reducing radiation dose to approximately one-quarter of the amount 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,” says 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,” says Johnson.

Performed at the Mayo Clinic in Scottsdale, Ariz., the study included a colon phantom that was imaged at 50 mAs (approximately 5 mSv) and 10-40 mAs (approximately 1-4 mSv) using six different ASIR levels. Eighteen patients were scanned using a standard CTC dose of 50 mAs and 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,” says Johnson.

The phantom study showed image noise reduction that correlated with a higher percentage of ASIR.

American Roentgen Ray Society

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Cleveland-based Radisphere National Radiology Group has signed contracts with Berwick Hospital Center, Berwick, Pa., and Lock Haven Hospital, Lock Haven, Pa., to provide on-site, night, and remote interpretation services to the hospitals’ radiology centers.

Mount Kisco Medical Group, Mount Kisco, N.Y., will use Ridgefield, Conn.-based CoActiv Medical’s Exam-Vault® Quad Redundant Archiving® to store its multi-modality imaging exams.

North Billerica, Mass.-based Lantheus Medical Imaging Inc. received a Supplier Pinnacle Award for outstanding performance as a contracted supplier from Premier Purchasing Partners LP of Charlotte, N.C.

Scarsdale Medical Group, Scarsdale, N.Y., has contracted with Charleston, S.C.-based Avreo, and will combine Avreo’s interVIEW system with Digisonic’s DigiNet Pro system to improve communication and increase workflow in its radiology department.

Philips Healthcare, Andover, Mass., signed a multi-year agreement to provide the Philips iSite PACS system to NYU Langone Medical Center’s radiology department.

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Atlanta-based Accelarad’s online medical image cloud computing service, SeeMyRadiology.com, has been installed by several facilities. Those facilities are: Fla.-based Orlando Health; Maryland-based Washington Open MRI; OMI, Gadsden, Ala.; Radiology Associates of Atlanta, Ga.; Atlanta Gastroenterology Associates, Ga.; Maspeth, N.Y.-based Ambulatory Vascular Care; and On-Site Imaging Solutions, Little Rock, Ark.

The SeeMyRadiology.com site enables the organizations to share images with outside facilities, physicians, and patients.