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44 votes
Accepted

Can MRI scans be dangerous for one's health?

One of the greatest benefits of MRI scans is their safety. Unlike PET, X-ray, CT and most other scans, MRIs use the properties of body tissues in magnetic fields to produce an image. The MRI machine ...
7 votes

Pacemaker and MRI

Some new pacemakers are MRI compatible ([1]). Of those, some have an exclusion zone where the body may not be scanned. I wouldn't be surprised if, in a few years, all new pacemakers and ICDs will be ...
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7 votes
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what does this abnormality (arachnoid cyst) mean in a brain MRI?

First of all, your "main question" contains a lot of small other questions, which I think are difficult to answer as we are not your sister's neurologist (we haven't seen the MRI, we haven't examined ...
5 votes
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How reliable is MRI to diagnose ACL (anterior cruciate ligament rupture)?

Nothing is more helpful than a comprehensive physical examination by an expert and the clinical course of the disease, for ruling out the ACL rupture. Evidence supports that The accuracy of the ...
  • 461
5 votes
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What does the intensity in an MR image represent?

There are no units for MRI intensity. A Comparison of Five Methods for Signal Intensity Standardization in MRI (CEUR-WS.org): A major problem in magnetic resonance imaging (MRI) is the lack of a ...
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5 votes

When is an MRI also an MRN?

If you are going to have a Magnetic Resonance Neurography (MRN), also known as MR Imaging of Peripheral Nerves (PNI) (UCSF), a doctor will likely tell you in advance, at least because the ...
  • 15.7k
5 votes

How important is the experience of the radiologist to diagnose a tendinopathy when reading an MRI?

Have a look at this publication of Sein et al., 'Reliability of MRI assessment of supraspinatus tendinopathy.' (PMID 17289860) Sein ML et al. Reliability of MRI assessment of supraspinatus ...
4 votes
Accepted

MR scanner versus MRI scanner

There is no consistency within the industry on the terminology. For example, GE calls them MR systems, Philips calls them both MR system and MRI system, Toshiba calls them both MRI system and MR ...
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4 votes
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Dangers of having MRI, CT-scan, & X-ray within a seven day period?

The amounts of radiation in today's machines is low enough that there is no negative impact to be expected. For comparison: X-Rays: A chest X-ray gives you about 10 mrem MRIs measure the reaction ...
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4 votes
Accepted

Do all neurodegenerative diseases show up on an MRI scan?

Neurodegenerative diseases are diagnosed on the basis of clinical symptoms (memory impairment for Alzheimer Disease/ bradykinesia, tremor and rigor for Parkinson Disease) +/- neuropsychological tests. ...
4 votes

What can you observe from MRI noises?

[TLDR: The gradient coils.] That is a great question. There are three parts to an MRI machine: main magnetic field (1.5 Tesla, 3 Tesla etc), gradient coil system and radio-frequency coil. The ...
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4 votes

Does diffusion MRI (DWI & DTI) measure diffusion or osmosis?

Diffusion of water. Osmosis is movement of water across a membrane due to solute changes. In the case of diffusion tensor MRI, the whole point is that there is more diffusion along the same axis as ...
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4 votes
Accepted

Does the age of an MRI scanner impact the quality of the scans?

This is more of a partial answer than a full answer. First, it would be useful to understand the typical amount of time an MRI scanner is in service. A report from the European Society of Radiology ...
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3 votes
Accepted

What kind of personal body scanning equipment can you legally buy?

In the US, medical device sales are regulated by the FDA much like drugs. Like drugs, some items are permitted for over-the-counter (OTC) sale to the public (for example, bandages and thermometers). ...
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3 votes

When is an MRI also an MRN?

Magnetic Resonance Imaging is an umbrella term for any medical imaging technique that makes use of the phenomenon of nuclear magnetic resonance. There are many variants depending on how the scanner is ...
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3 votes
Accepted

How to request copies of CT-Scans, MRI, X-rays & ultrasound/endoscopic imagery from Dr.'s/Surgeons for personal records? Possible?

Regarding United States, quote from "Copy Fees and Patients’ Rights to Obtain a Copy of Their Medical Records: From Law to Reality" (2005): Patients have a legal right under HIPAA to a copy of ...
3 votes

What to do when an earthquake hits while inside a MRI?

You most definitely do not want to be in an MRI machine during an earthquake. The superconducting magnets in an MRI scanner are cooled by liquid helium. If the cooling system is damaged and there is a ...
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3 votes
Accepted

What to do when an earthquake hits while inside a MRI?

Do nothing, stay inside the MRI machine. I never performed MRI scan in the past but I had experience of several quite big earthquakes within the last 10 years. So I provide my thought on this for ...
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3 votes

Is there commercially available MRI or CT that can be used for anthropometric rather than diagnostic purposes?

CT scans use ionizing radiation. It's safe to get a CT scan for a medical purpose: the marginal risks of the scan are outweighed by the diagnostic benefits. However, repeated CT scans can potentially ...
  • 12.5k
3 votes
Accepted

What would be the consequence if one does not drink a lot of water immediately after an MRI with contrast agent (intravenously injected)?

Toxicity of gadolinium-based contrast agents can generally be classified as acute (short term) and chronic (longer term) and include¹: Acute allergic-like reactions Acute physiologic reaction Chronic ...
  • 2,589
2 votes

MRI scans for diagnosing Crohn's disease?

As far as I know MRI scans are mainly used to assess the location and extent of crohn's disease manifestations and crohn's associated complications (strictures, fistulas, wall thinkening). MRI is ...
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2 votes

Number of MRI scanners in the world today?

Magnetic-resonance.org World­wide, there are approximately 36,000 MR machines. At present, about 2,500 MR imaging units are sold worldwide every year This CDC link shows the amount per country. ...
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2 votes
Accepted

What criteria should I pay attention to when choosing a place to perform an MRI?

A higher Tesla magnet generally equates to a higher quality image. Closed (the traditional round-shaped magnet bore) or oval MRIs generally produce a higher quality image than open MRIs, so avoid an ...
  • 237
2 votes

How can an MRI influence the treatment in case of an elbow tendinopathy?

I think it is mainly due to the evidence indicating poor accuracy (sensitivity and specificity) of conventional MRI. It means that false-positive or false-negative findings may be detected in MRI of ...
  • 461
2 votes

What to do when an earthquake hits while inside a MRI?

Via the UCLA Brain Mapping Center, in the event of (emphasis and formatting added): Non-Fire Facility Emergencies Unscheduled Power Shutdowns Earthquakes Magnet Quench (catastrophic ...
  • 12.5k
2 votes

What is the difference between a regular and full body MRI?

It's indeed the same "big magnet" machine as for normal MRI, but in WB-MRI (ideally) multiple coils are placed on the patient's body, e.g.: The process does indeed last 30-60 minutes (as ...
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2 votes

Where can I find head MRI files?

Brain Imaging Data Structure (BIDS) is a simple and intuitive way to organize and describe neuroimaging and behavioral data. You can find it on bids.neuroimaging.io. BIDS is heavily inspired by the ...
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2 votes

What are normal structures that could be misinterpreted as lacunar strokes on T1 or T2 brain MRI?

So far I have found Dilated Virchow-Robin (VR) Spaces (a.k.a dilated perivascular spaces) which are not necessarily malign and have pretty much the exact aspect on T1 and T2. Ref: https://pubs.rsna....
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2 votes
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Why do MRI Scan and CT Scan take more time than X- Ray?

An xray is one image. Sometimes they might take a few more. CT and MRI scans are many more images. What's more, they aren't all taken from the same place, so you have to be moved into position a few ...
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