News | August 09, 2010

Researchers Say New Protocol May Lower CT Dose by Nearly 50 Percent

August 9, 2010 - Researchers at Mayo Clinic are working to reduce radiation dosages used to acquire perfusion and other CT images.

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.

“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,” said Cynthia McCollough, diagnostic radiologist, Mayo Clinic.

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.

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.”

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, 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.”

For more information: www.mayo.edu

Related Content

Clinical Trial Testing Topical Gel to Reduce Breast Density
News | Breast Density | June 19, 2018
Women with dense breast tissue soon might be adding a new product to their skincare routine to help them fight breast...
New Prostate Cancer Radiotherapy Technique Aims to Preserve Sexual Function
News | Radiation Therapy | June 18, 2018
A multicenter clinical trial being led by UT Southwestern physicians is testing a technique for sparing nerve bundles...
Report Finds Identifying Patients for Lung Cancer Screening Not So Simple
News | Lung Cancer | June 18, 2018
New findings in the current issue of The American Journal of Managed Care suggest that getting the right patients to...
Weight-Bearing CT International Study Group Hosts  Scientific Session at AOFAS Conference
News | Computed Tomography (CT) | June 15, 2018
June 15, 2018 —The Weight-Bearing CT International Study Group will host a scientific session on the benefits of weig
Florida Hospital First in State to Adopt NeuroLogica's BodyTom Elite CT
News | Computed Tomography (CT) | June 14, 2018
June 14, 2018 — NeuroLogica, a subsidiary of Samsung Electronics Co.
Riverain Technologies Issued U.S. Patent for Vessel Suppression Technology
News | Computed Tomography (CT) | June 14, 2018
Riverain Technologies announced that the United States Patent and Trademark Office (USPTO) has awarded the company a...
360 Photos | 360 View Photos | June 14, 2018
This is a 360 degree image from the Canon Aquilion 64-slice...
PET/CT Changes Care for 59 Percent of Suspected Recurrent Prostate Cancer Cases
News | Prostate Cancer | June 13, 2018
A recently presented investigational clinical trial evaluated the impact of 18F fluciclovine positron emission...
American Society of Neuroradiology Honors Peter Chang with Cornelius G. Dyke Memorial Award
News | Neuro Imaging | June 13, 2018
Peter Chang, M.D., current neuroradiology fellow at UCSF and recently recruited co-director of the UCI Center for...
Accuray TomoTherapy System Beneficial in Two Total Body Irradiation Studies
News | Radiation Therapy | June 13, 2018
Recently published data from two new studies demonstrate the benefits of Accuray’s TomoTherapy System in the delivery...
Overlay Init