Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unindicated CT series result in unnecessary radiation exposure for patients

30.11.2009
A large proportion of patients who undergo abdominal/pelvic computed tomography (CT) receive unindicated and unnecessary additional image acquisition resulting in excess, avoidable radiation exposure, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

"It is the responsibility of all physicians who work with ionizing radiation to ensure that the dosage is as low as reasonably achievable without compromising the patient's well being," said Kristie Guite, M.D., radiology resident at the University of Wisconsin (UW) in Madison. "Our study found that this principle is not being followed in many practices."

A CT examination consists of imaging the patient using a CT scanner and sometimes involves the injection of an intravenous contrast agent. Imaging can be performed at multiple time points before and/or after the injection of the contrast material. Each image acquisition is referred to as a "series." Although having multiple series can be helpful for some conditions, they are not generally necessary.

Because it provides valuable diagnostic information, CT use has risen rapidly. In recent years, a number of reports have highlighted the increasing radiation exposure to patients through the use of medical imaging, particularly CT. While these reports have often focused on general and screening uses, little attention has been paid to radiation from additional series, including routine non-contrast or delayed-phase CT, which may or may not be indicated by the patient's condition but are sometimes performed so that nothing is overlooked.

To determine the frequency of unindicated additional scanning and the resultant excess radiation exposure to patients, the researchers reviewed the appropriateness and radiation dose of abdomen and pelvis CT exams for 500 patients performed at outside institutions and submitted to UW – Madison for interpretation. The patients ranged in age from nine months to 91 years, with most between 30 and 50 years old.

There were a total of 978 series for the 500 patients. Using the American College of Radiology (ACR) Appropriateness Criteria®, 35.3 percent (345/978) of the CT series in 52.2 percent (261/500) of the patients were determined to be unindicated. The most common unnecessary exam was delayed-phase imaging, accounting for 268 (77.7 percent) of the 345 unnecessary series. In delayed-phase imaging, several images of the same region are obtained a short period of time after contrast injection to detect changes. Among the 500 patients, the mean excess radiation dose per patient from unnecessary scans was 11.3 millisieverts (mSv), equivalent to the dose received from 113 chest x-rays or three years of naturally occurring background radiation.

"We suspect that at many institutions there is a lack of focus on selecting CT protocols tailored specifically to answer the clinical question," said coauthor J. Louis Hinshaw, M.D., assistant professor of radiology at UW – Madison. "It is certainly easier to select an 'every size fits all' approach."

The researchers also noted a possible connection in some cases between additional scanning and increased payment, such as performing both non-contrast and contrast-enhanced scans when only one series was indicated.

Efforts are ongoing to protect patients from unnecessary radiation exposure from medical imaging procedures, including the Image Gently initiative for safety in pediatric radiology and an ACR-RSNA task force for adult radiation protection. In addition to following strict appropriate imaging utilization standards, radiologists and medical physicists stress the importance of minimizing dose without sacrificing diagnostic ability. Advances in CT technology over recent years have markedly decreased dose while maintaining optimal image quality.

Dr. Guite advises patients not to be unduly alarmed when their physician orders a CT exam.

"The use of CT has been a huge benefit to human health," she said. "When used appropriately, the benefits of the diagnostic information obtained with CT far outweigh the potential risks."

Dr. Hinshaw suggests that patients ask their physicians about the risks and benefits of the proposed exam and inquire at the CT facility as to the number of series that will be performed, and if a smaller number of series would be sufficient.

Coauthors are Frank N. Ranallo, Ph.D., and Fred T. Lee, M.D.

Note: Copies of RSNA 2009 news releases and electronic images will be available online at RSNA.org/press09 beginning Monday, Nov. 30.

RSNA is an association of more than 44,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)

Editor's note: The data in these releases may differ from those in the printed abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.

Linda Brooks | EurekAlert!
Further information:
http://www.rsna.org
http://RadiologyInfo.org

More articles from Medical Engineering:

nachricht Visualizing gene expression with MRI
23.12.2016 | California Institute of Technology

nachricht Illuminating cancer: Researchers invent a pH threshold sensor to improve cancer surgery
21.12.2016 | UT Southwestern Medical Center

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>