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Will heart beat be affected by MRI?

by oem7110
Tags: affected, beat, heart
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oem7110
#1
Mar12-12, 10:25 AM
P: 151
There is a hugh amount of magnetic field during MRI scanning, I would like to know whether our heart beat rhythm will be affected by this magnetic field or not if the magnetic field is too strong.
Does anyone have any suggestions?
Thanks in advance for any suggestions
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Evo
#2
Mar12-12, 12:13 PM
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Quote Quote by oem7110 View Post
There is a hugh amount of magnetic field during MRI scanning, I would like to know whether our heart beat rhythm will be affected by this magnetic field or not if the magnetic field is too strong.
Does anyone have any suggestions?
Thanks in advance for any suggestions
MRIs are performed on a specific part of the body. For example, I have had lower back MRIs and a head MRI.

If you are referring to cardiac MRIs, no, there is no danger to the heart.

Cardiac MRI produces no side effects from the magnetic fields and radio waves.
http://cardiosmart.org/HeartDisease/CTT.aspx?id=218
oem7110
#3
Mar12-12, 05:46 PM
P: 151
Quote Quote by Evo View Post
MRIs are performed on a specific part of the body. For example, I have had lower back MRIs and a head MRI.
If you are referring to cardiac MRIs, no, there is no danger to the heart.
http://cardiosmart.org/HeartDisease/CTT.aspx?id=218
When there is a hugh amount of magnetic field getting through the body, will it create a Voltage spike? and cause our body disfunction for a short time?
Thanks you very much for any suggestions

Evo
#4
Mar12-12, 05:57 PM
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Will heart beat be affected by MRI?

Quote Quote by oem7110 View Post
When there is a hugh amount of magnetic field getting through the body, will it create a Voltage spike? and cause our body disfunction for a short time?
Thanks you very much for any suggestions
From an MRI?
oem7110
#5
Mar12-12, 06:06 PM
P: 151
Quote Quote by Evo View Post
From an MRI?
It could be from Geomagnetic / Solar Storm from Space, who works in Space station.
Any suggestions?
Drakkith
#6
Mar12-12, 06:20 PM
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No, the strength of even the MRI machine, which is MUCH higher than anything else you will ever experience in your life, is too small to have any negative effects on you. You're body is not a conductor in a circuit and will not experience any voltage spikes or anything.
lisab
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Mar12-12, 06:33 PM
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Quote Quote by oem7110 View Post
There is a hugh amount of magnetic field during MRI scanning, I would like to know whether our heart beat rhythm will be affected by this magnetic field or not if the magnetic field is too strong.
Does anyone have any suggestions?
Thanks in advance for any suggestions
The magnetic field won't be strong enough to cause heart trouble. MRIs are very safe.

I've had several - let me tell you what you might experience.

First, they're pretty loud. The technician will probably give you headphones for your ears.

The space you fit into is very small. Some people who have claustrophobia may not be able to have an MRI done. The technician will probably ask you if you're comfortable in small spaces.

The scans last much longer than an X-ray. One I had was almost 45 minutes.

If your heart starts to pound during the test, it's probably because you're nervous. If you get too nervous, the technician can stop the test.

Once it gets started and you realize everything is OK, just try to relax - maybe nap, if you can.

If you have more questions about it, or still feel ill-at-ease, you should discuss it with your doctor.
Evo
#8
Mar12-12, 06:38 PM
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Quote Quote by oem7110 View Post
It could be from Geomagnetic / Solar Storm from Space
For humans on earth, no. You know you can google this as easy as I can.

Flares Affect Heart Rate?

Can the energy from powerful solar flares affect the electrical signals originating within the human heart? Can powerful solar flares, like the ones that hit the Earth in November 2000, cause an arrhythmia in a person's heart rate?
The Earth's atmosphere and magnetic field give us enormous protection from the effects of solar flares. Most of the effects here on the ground are actually due to the fact the solar flares can deform the Earth's magnetic field. This deformation is far too small to affect electric signals in the human body. But the changing magnetic field can cause large currents in long conductors such as the power distribution network, oil pipelines, etc. There may also be an increase in radiation, especially for planes that fly over the poles, but it is not considered a serious risk. Astronauts and satellites outside the atmosphere can be affected by the energetic particles in the solar flare, and if they are outside the Earth's magnetic field it can be even worse.

Dr. Eric Christian
(December 2000)
http://helios.gsfc.nasa.gov/qa_sw.html#heart


who works in Space station.
Read this.
This phenomenon, known as the "Forbush decrease" after the scientist who discovered it, has been observed repeatedly. The effect can be dramatic and sustained. During one spate of solar storms in 2005, for example, cosmic-ray exposure on the space station decreased by 30 percent, NASA officials have said.

So while big solar storms can be destructive — disrupting power and communications infrastructure around the world — their massive power can also do some good, creating a protective bubble around astronauts floating hundreds of miles above Earth.
http://www.space.com/10904-solar-sto...e-station.html
Evo
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Mar20-12, 10:15 AM
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Quote Quote by herberex11 View Post
copyright violation
You failed to post links to the articles you copied from. Nothing in this post was yours. Copyright violations are against the law and against the rules, so your post had to be deleted.
cbhattarai
#10
Mar22-12, 04:54 AM
P: 1
I have never gone through such type of test, but i would like to know taht does it scare you..
mfenty
#11
Apr19-12, 11:03 AM
P: 5
I've worked in an academic MRI research lab for several years. The answer is - complicated.

1) For clinical scans that you will get (3 Tesla or lower) the magnetic field from the scanner will not affect your heart.

2) MRI creates images from RF waves coming from an antenna close to the body. The antenna transmits RF with potentially high power and potentially long durations. There is a risk of burning tissue with RF fields during the scan. Therefore it is possible to damage the heart.

3) MRI requires field gradients to be turned on and off very quickly. This high amount of magnetic flux can cause eddy currents to build along the length of neurons in the body. Theoretically, you can damage the AV node and subsequent neurons of the heart to alter the beating. Therefore it is possible to damage the heart this way.

4) Clinical scanners are heavily controlled by both hardware and software limits on power deposition (SAR) and gradient switching. Therefore it is almost impossible for your heart to be affected.

5) Lastly, ultra-high field scanners (7T and above) blood begins to act differently and may become more viscus due to the hemoglobin (iron) in the red blood cells. The change of blood viscosity may be able to affect heart beat and stability of the heart.
Drakkith
#12
Apr19-12, 03:10 PM
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Mfenty, what do you do at an "MRI research lab"? Do you do MRI's on people? If not, do you use the same field strength and RF intensity as a medical MRI used on people?
mfenty
#13
Apr19-12, 03:21 PM
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Drakkith - I worked here for a little under 5 year (http://cmroi.med.upenn.edu/) The site is being updated so some of the links may be dead. That group had the first MRI scanner in 1984 (serial number 1) and has been doing work in the field since then. We do a lot of clinically-translatable work on 1.5 and 3 Tesla machines that eventually becomes licensed to manufacturers like GE and Siemens. Here is a link of the groups' papers - http://www.ncbi.nlm.nih.gov/pubmed?t...20pennsylvania


Personally, I worked on developed ways we can get the scanner to generate images in people, animals, and test tubes. I scanned people at 1.5T, 3T, and 7T (research scanner only), and guinea pigs at 9.4T. I developed hardware (antennas) for specialized imaging applications and software applications (C++ and MatLab) for image reconstuction - all images are in Fourier Space and need to be transformed quickly. There are antennas made for all body parts (look here - http://www.invivocorp.com/coils/) . I worked with orthopaedic surgeons to figure out what there unmet imaging needs were and worked with our team to try to alleviate the problems.

Hope that helps.
daveb
#14
Apr19-12, 03:34 PM
P: 926
MRIs can also adversely affect the skin area around tattoos (light burns due to iron content in some tattoo inks).
Drakkith
#15
Apr19-12, 03:49 PM
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If you went to a hospital and had an MRI, would that involve the same dangers as that of your research MRI Mfenty?
mfenty
#16
Apr19-12, 05:05 PM
P: 5
Daveb - There are a lot of dangers associated with MRIs, I was trying to keep things focused on the heart

Drakkith - I would say the most dangerous thing about getting an MRI is having metal on/around/near you (not including MRI-safe implants). The FDA sets very conservative limits on SAR deposition and gradient slew rates (how quickly eddy currents can form) so really the dangers are human-related. Having earrings, necklaces, metal in eye, bullet fragments, metal in gut, etc. is the dangerous thing.

That said, it is not impossible for the scan to be "SAR-safe" and still be hurt. While the RF frequencies used for imaging (40-128 mHz) aren't really high enough to cook you, the long duration of some pulses may burn superficial tissues. MRI contrast agents, mainly gadolenium, is known to cause Kidney failure in patients with prior histories of kidney issues so that is also a danger. However, MRIs are still safer than CT, PET, or XRAY
Drakkith
#17
Apr20-12, 06:12 AM
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Ah ok. Thanks for clarifying.
sophiecentaur
#18
May15-12, 09:17 AM
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I had an abdominal MRI scan recently (1.5T) and I reckon that I was aware of a slight heating effect. Is that possible or was it just subjective? I was not worried by the procedure so not 'wound up' at all.
Amongst all the noise I managed to doze off for a minute or two (naff all else to do and I had to stay still) but I was sure that I felt a bit of local heating 'down there'.


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