MRI scanners affect concentration and visuospatial awareness

August 29, 2012

Standard head movements made while exposed to one of the three electromagnetic fields produced by a heavy duty MRI scanner seem to temporarily lower concentration and visuospatial awareness, shows an experimental study published online in Occupational and Environmental Medicine.

The effects were particularly noticeable in tasks requiring high levels of , which may have implications for surgeons and other working within the vicinity of an , the research indicates.

(MRI) uses strong magnetic fields and to take very detailed pictures of the brain and spine. Three types of electromagnetic fields are required to create an image: static; switched gradient; and radiofrequency.

The static magnetic field is always present, even when no imaging is taking place.

Thirty one volunteers made standard head movements within the static magnetic field of a higher field 7 Tesla MRI scanner at exposure levels of zero (sham), 0.5 (medium), and 1 (high)Tesla, in a random order, one week apart.

After each exposure level, the volunteers were set 12 timed , designed to test the sorts of skills that a surgeon or other healthcare professional might need to deploy within the vicinity of an MRI scanner.

These included visual tracking and movement, as well as more general functions, such as attention, concentration and working memory. The tests were neutral in that they didn't test intelligence or depend on practice.

In all, 30 volunteers completed all three sessions. Compared with the sham test, the results showed that the more general functions, such as attention and concentration, and visuospatial awareness were significantly affected.

For complex , reaction and disengagement times were longer, varying from 5% to 21%, the higher the level of Tesla exposure.

Complex tasks rely on working memory, suggesting that less of this is available to keep the same levels of attention and concentration going at higher levels of exposure, say the authors.

While non-verbal memory did not seem to be affected, there was a fall in verbal memory, although this only reached borderline significance. At the highest level of exposure, volunteers also experienced some physical symptoms, including metallic taste in the mouth (12 people), dizziness (6), headache (5), and nausea (1).

"The exact implications and mechanisms of these subtle acute effects in [practice] remain unclear," write the authors.

But the introduction of increasingly more powerful MRI machines has boosted exposure levels to static for both patients and staff, they say.

"To date, mainly health and safety concerns for patients have been evaluated, but possible consequences are particularly important for professionals......cleaners, and MRI engineers since they are repeatedly exposed to static magnetic fields," they add.

Explore further: The effects of weak magnetic fields on cancer cells and other aspects of biology

More information: Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double blind randomised crossover study, doi 10.1136/oemed-2011-100468

Related Stories

The effects of weak magnetic fields on cancer cells and other aspects of biology

April 23, 2012
We are surrounded by a constantly changing magnetic field, be it the Earth's or those emanating from devices, such as cell phones. Carlos Martino, an assistant professor at the University of Nevada, Reno, is interested in ...

What causes MRI vertigo? Machine's magnetic field pushes fluid in the inner ear's balance organ

September 22, 2011
A team of researchers says it has discovered why so many people undergoing magnetic resonance imaging (MRI), especially in newer high-strength machines, get vertigo, or the dizzy sensation of free-falling, while inside or ...

Researchers use improved imaging technique; discover a better approach to diagnosing epilepsy

August 1, 2011
Using state-of-the-art, 7 Tesla magnetic resonance imaging (MRI) technology, University of Minnesota Medical School researchers may have uncovered a better approach to diagnosing epilepsy.

Recommended for you

Make way for hemoglobin

August 18, 2017
Every cell in the body, whether skin or muscle or brain, starts out as a generic cell that acquires its unique characteristics after undergoing a process of specialization. Nowhere is this process more dramatic than it is ...

Bio-inspired materials give boost to regenerative medicine

August 18, 2017
What if one day, we could teach our bodies to self-heal like a lizard's tail, and make severe injury or disease no more threatening than a paper cut?

Female mouse embryos actively remove male reproductive systems

August 17, 2017
A protein called COUP-TFII determines whether a mouse embryo develops a male reproductive tract, according to researchers at the National Institutes of Health and their colleagues at Baylor College of Medicine, Houston. The ...

Two-step process leads to cell immortalization and cancer

August 17, 2017
A mutation that helps make cells immortal is critical to the development of a tumor, but new research at the University of California, Berkeley suggests that becoming immortal is a more complicated process than originally ...

Are stem cells the link between bacteria and cancer?

August 17, 2017
Gastric carcinoma is one of the most common causes of cancer-related deaths, primarily because most patients present at an advanced stage of the disease. The main cause of this cancer is the bacterium Helicobacter pylori, ...

New Pathology Atlas maps genes in cancer to accelerate progress in personalized medicine

August 17, 2017
A new Pathology Atlas is launched today with an analysis of all human genes in all major cancers showing the consequence of their corresponding protein levels for overall patient survival. The difference in expression patterns ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.