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 Noninvasive eye scan could detect key signs of Alzheimer's years before patients show symptoms
18.08.2017 | Cedars-Sinai Medical Center

nachricht Water-filtered infrared-A (wIRA) overcomes swallowing disorders and hypersalivation – a case report
10.08.2017 | Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e.V.

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>