A Magnetic Resonance Imaging (MRI) machine may look intimidating, however, many refer to MRI as one of the safest diagnostic examinations because it does not utilize ionizing radiation. MRI has been studied and proven to be safer (biologically) than any other clinical test that uses ionizing radiation (Hartwig, Givanetti, Vanello, Lombardi, Landini & Simi, 2009). Lets take a look to see if it is in fact, the safest radiologic examination.
Photo Source:
GE SIGNA 1.5 TESLA ECHOSPEED SHORT BORE MRI 63 MHz (Manufactured 2003) CXK4 MAGNET [Web Photo]. Retrieved from http://www.biomedicaldepot.com/ge-signa-1-5t-mri/
Sagittal Lumbar Spine MRI [Web Photo]. Retrieved from http://www.evesbreastcenter.com/Services/MRI/mri.html
Sagittal Lumbar Spine MRI [Web Photo]. Retrieved from http://www.evesbreastcenter.com/Services/MRI/mri.html
Sources:
Hartwig, V., Givanetti, G., Vanello, N., Lombardi, M., Landini, L., & Simi, S. US National Library of Medicine, National Institutes of Health Search termSearch database. (2009). Biological effects and safety in magnetic resonance imaging: A review (10.3390/ijerph6061778). Retrieved from website: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705217/
There are numerous signs adorning the doorway to every MRI scanner. Signs are the only visual indicator that dangers are present.
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"DANGER! Powerful Magnet Always On" MRI Safe Warning Sign or Sticker [Web Graphic]. Retrieved from http://www.universalmedicalinc.com/Magnet-Always-On-MRI-Safety-Signage-p/mtm1366-01-umi.htm
Danger Restricted Access Strong Magnetic Field. [Web Graphic]. Retrieved from http://www.safetysign.com/products/p19475/danger-restricted-access-label
The dangers of MRI are from the items you cannot see. The first is the electromagnetic field. This diagram shows a representation of where the 5 gauss line is located. Electromagnetic fields are 3 dimensional around the magnet. Outside the 5 gauss line is considered to be the ‘safe’ zone of the magnet. In most facilities the range of the 5 gauss is confined within the scan room.
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MRI scanning room [Web Drawing]. Retrieved from https://www.attainia.com/templates/room.cfm?MRI-Scanning-Room-(XMRS1)&roomid=49554&CFID=1511135&CFTOKEN=6ca2ff95e801531d-DCA2B466-F707-54D9-38B2EB2ED1831935
Ferromagnetic items within the 5 gauss zone can become instant missiles. A paperclip can reach speeds up to 40 mph ("Mri safety, " ). The National Quality Forum recognizes MRI projectiles as a TOP TEN Serious Reportable Event (“Mri safety, ”). To date, in the US there has been one death caused by an ferromagnetic oxygen tank becoming a missile and pinning the patient into the machine.
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40MPH [Web Graphic]. Retrieved from http://www.roadtrafficsigns.com/speed-limit-sign/speed-40-mph-sign/sku-x-w13-1-40.aspx
Karatopis, A. (2014, September 17). Negligence of safety measures! [Online forum comment]. Retrieved from https://www.facebook.com/groups/238830782851741/
Karatopis, A. (2014, June 18). MRI disarms a non cooperative patient. [Online forum comment]. Retrieved from https://www.facebook.com/groups/238830782851741/
MRI Accidents [Print Photo]. Retrieved from http://www.koppdevelopment.com/mri_accidents.html
Sources:
Mri safety . (n.d.). Retrieved from http://www.ferroguard.com/mri-safety/
If one takes a look at the electromagnetic spectrum of radio waves they will find that MRI is located near the frequency of TV’s and microwaves. Therefore, heating of a patient is a big concern. As seen in the pics, patients can receive delayed burns from skin to skin contact within the machine.
Photo Sources:
Brown, G. (2014, September 14). Case study of burns from skin to skin contact in mri [Online forum comment]. Retrieved from https://www.facebook.com/groups/8436883238/?fref=nf
Electromagnetic spectrum [Web Photo]. Retrieved from http://www.gsma.com/publicpolicy/faq/electromagnetic-spectrum
Click on the sound icon.
Of course the MRI machine does not play the tune of ‘Smoke on the Water’ but that is a sample of the sounds that a patient can hear during their scan. An MRI machine The scanners can produce up to 140 dB and still meet the IEC and FDA limits, and often output > 130dbA. Standard guidelines are to limit patient sound levels to < 99bDA with adequate hearing protection, and technologists are required to be competent in the proper use of adequate hearing protection. Some people appear to be more sensitive, children certainly are.
Sound Source:
Logan, B. (Producer) (2012). Mri music [Web]. Retrieved from http://youtu.be/CH9f8tcMAIQ
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Noise Levels [Web Graphic]. Retrieved from http://www.quietys.com/en/moins-de-bruit/bruit
This figure shows the growth since 2000. The blue line shows the incident growth of up to 523% but now has began to show signs of decreasing. However, the volume growth has been a steady incline to approx 103% since 2000.
This figure shows the changes in the guidelines and recommendations to MRI in relation to the incident growth.
In 2001, Micheal Colombin, a 6 year old boy, was killed while having an MRI after a nurse brought an ferromagnetic oxygen tank into the scan room. The oxygen tank became a missile and caused fatal head trauma to the child. The results show a significant decrease in incidents following the tragedy. In my opinion, it is because technologists realized the dangers of the magnet and the general public became aware as well.
The purple lines represent the changes The Joint Commission imposed and the blue light blue lines represent the changes and recommendations set forth by the American College of Radiology.
In the world of MRI there is rarely such a thing as ‘safe’ and ‘not safe’; that would be too simple. As you can see (from an excerpt of mrisafty.com) there are eight conditional levels of an item being safe and two conditional levels of an item being unsafe. To make this even more confusing, a 3T (Tesla) magnet is stronger than a 1.5T magnet but items that are safe in a 3T machine are not always safe in a 1.5T machine.
Photo Source:
Screenshot of homepage [Web Photo]. Retrieved from http://www.mrisafety.com/
To date there are no governing bodies of MRI. The ACR and TJC have made recommendations for safety and some insurances arent reimbursing facilities that refuse to follow the guidelines. However, more education, better training for technologists and radiologists is needed, as well as the implementation of MRI safety officers. There are many facets to the MRI safety world and a dedicated, knowledgeable individual can make a difference for patients, technologists and visitors.
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Dr. Kanal [Web Graphic]. Retrieved from http://mrisafetycourse.com/about.php
A little ‘iron-fortified’ breakfast cereal does a body good!
Lucky this doesn’t happen or we all would be in trouble.
Thank you!
Photo source:
Morparia, H. (Photographer). Radiology Cartoons by Dr. Hemant Morparia [Web Drawing]. Retrieved from http://refindia.net/rindia/cartoons/cartoon26.htm
