First Image Taken With an Ultra Low Field MRI

KentuckyFC writes "MRI machines are about to get smaller, much smaller. Most of their bulk is taken up by the huge superconducting magnets required to generate fields of a few Teslas. Now a team at the Los Alamos National Lab in New Mexico has built a machine that can produce images using a field of only a few microTesla (PDF, abstract here). So giant superconducting magnets aren't necessary, a development that has the potential to make MRI machines much smaller, perhaps even suitcase-sized. The one-page paper shows sections of the first 3D brain image taken with the device."

Comments

Hidden monkeys

[LiquidCoooled]

I thought the images were of monkeys at first, however when I went to have a look at MRI images of a human head was thankfully proven wrong (some of us have our monkey origins hidden better than others).

So, for comparison here is a page with images of human heads in a normal MRI.
(single image here)

I hope they get the focusing better (which is what I understand the power is used for) because this will be a good progression.

Article's title is misleading

[IvyKing]

This may be the first image of a human head with an ultra low field MRI, but ULF MRI images have been made for at least a decade and a half. Magritek, a New Zealand company, makes a low cost unit ULF MRI system, though the image volume is limited to about one liter.

Another company, Vista Clara, is using a novel form of ULF MRI to map groundwater.

Re:Article's title is misleading

[ceoyoyo]

The summary is VERY incorrect.

This isn't an ultra low field MRI, it's a DUAL field MRI. In a normal scanner you have a big, static magnetic field that polarizes the sample and remains for readout. In one of these dual field scanners you use the big field (or a bigger field, it's usually a resistive electromagnet so it can't be anywhere near as strong as a superconductor) to polarize the sample then you shut it off and use a much smaller field for readout. There are a few advantages, the one the abstract focuses on is that you can do things like MEG in a very low field. The other is that energy deposition is related to the field strength so by using a small field you can use imaging sequences that would otherwise pump too much energy into the subject.

One of the guys working on this technology visited my lab last year. It was a very interesting presentation.

I believe someone has produced an MR image using the Earth's magnetic field. They've certainly done nMR in the Earth's field. You can't get much lower than that on this planet.

Re:Article's title is misleading

[Anonymous Coward]

Earth's field and low field MRI are actually relatively common. There has even been NMR work done at ~1uT in a shielded chamber.

Stronger pre-polarizatin field is used

[flyingfsck]

Hmm, they use a prepolarization field of 30 mT for 1 second before using the weaker measurement field of 46 uT. So I'm wondering why they don't just use the 30 mT field and be done with it.

Re:Stronger pre-polarizatin field is used

[IvyKing]

The Larmour frequency for 30 mT is about 1.28 MHz, which is in the AM broadcast band. Interference is likely to be a significant problem.

MRI accidents

[l00sr]

Hopefully this will also put an end to those pesky MRI accidents. Not that they're common, but still, those things aren't toys.

other implications

[SuperBanana]

Off the top of my head, some plusses and negatives.

Plusses: less (very expensive) liquid helium or (less expensive but still $$) liquid nitrogen. Less of a magnetic field means much higher MRI safety; everything from oxygen cylinders to chairs to guns have been drawn into/against MRIs (the gun was a prison guard who got pushy and DEMANDED to be in the same room as a prisoner. Yeah, the gun went off. No, nobody was hurt.)

Negatives: since the MRI isn't as strong, it might be more affected by local magnetic fields from wiring, ferrous objects, etc. Dunno. Right now, MRIs are installed into big rooms that have as little ferrous material as possible, and then very carefully "shimmed" to adjust for the building and local magnetic fields by a technician. Even if an MRI gets down to "suitcase" size, the necessity of a "clean" environment and calibration for each location might make moving them around very tough.

As a side note, there are already shielded MRI machines which work in a trailer and require little setup time, but being outdoors makes things easier- no building infrastructure to mess with the magnetic fields.

Re:other implications

[2short]

Ten years ago my girlfriend at the time was involved in research using NIHs 4T human machine, a 3-story tall superconducting magnet. There was a fence outside part of the building with signs saying keep out, strong magnetic fields. But one day my girlfriend told me how the director had to go running outside because some workmen digging a trench were taking down a section of the fence, preparing to bring a backhoe through. After arguing a bit with the construction foreman about this being where the trench was supposed to go, and how he really didn't think a magnet was going to hurt his backhoe, she took one of their shovels and stuck it to the wall. That got their attention long enough to explain how many millions of dollars they would owe her if their backhoe gets sucked though the side of the building and breaks her magnet.

Re:other implications

[tgilk]

Man, I'd love to get the details on that! I'm an architect that specializes in MRI facility design & construction and I'd love to be able to document that story.

Another similar story, an MRI facility in Arkansas had just been built and the Fire Marshal was on his way to do the final inspection. However, before he got there, the sprinkler contractor decided to take the oxyacetylene torch rig into the room to fix a leaky sprinkler head. The magnet grabbed the tanks, drew them inside, snapped the valve off, the spark from which ignited the gases. The fire caught the magnet and building on fire, totaling both.

I hope they do away with the tunnels

[pair-a-noyd]

I had to have several MRI & CT scans and that friggin tunnel is more than I can handle.
They tried to put me in one with the normal little tunnel (about as big around as a five gallon bucket) and I freaked out before I got 2' into it and made them back me out. Then they put me in an "open" MRI machine but it was like being crushed under a car. No way Jose. Abort #2.
So I went to another city where they had a different kind that was a little more "open" than #2.
This one then pumped me full of Xanax and I survived it.

The CT scan was not quite as bad because it was like a large doughnut and there was only about 1' of my body inside it but it still freaked me out.
Xanax on that one too.

I swore I'll die before I ever go in one of those damn things ever again.
They need to come up with a better way. Some people can't handle that crap.
I hope these new ones are a break away from the "trapped in a pipe" or "crushed under a car" machines.

Re:I hope they do away with the tunnels

[Dunbal]

For some reason I find that your comment suits your screen name just fine...

Of course I understand completely that people don't have to justify their phobias, but you have to admit that you must have caused quite a few shaken heads, raised eyebrows, and sighs of exasperation on behalf of the medical staff. Especially considering that because of their scarcity such machines usually have a line of people waiting for them.

Re:I hope they do away with the tunnels

[RallyNick]

I had to have several MRI & CT scans and that friggin tunnel is more than I can handle.

Why not use a cloth eye cover?

Re:I hope they do away with the tunnels

[kailoran]

I'd assume those shaking heads were muttering "geez, another one" rather than "omg wtf how can someone be afraid of it". Claustrophobia isn't all that unheard of, and being shoved into a friggin pipe is somewhat a powerful trigger.

Re:I hope they do away with the tunnels

[Nyago]

If it were easy (or even moderately hard) to control a phobia, I suspect most people would. Justification is irrelevant. It matters only that the fear exists. Conquering a phobia typically requires exposure (with neutral or rewarding consequences) to the fear-provoking stimulus. In his case, gradual exposure to being in the tube.

I realize that many people find it difficult to understand the lack of control inherent in a phobia. I (with my injection phobia) am often told (by medical professionals) simply to get over it. Unfortunately, when a needle is present, I descend into blind animal panic. My rational mind ceases to function. The thoughts of controlling and pushing through the fear don't even occur to me. It is a pure flight-or-fight response, and I have done both.

Additionally, the guilt of having wasted time (of the doctors or other patients) needlessly adds to the unpleasantness of the situation. His attempts to undergo the procedure are, in my opinion, courageous.

People need help, not guilt or reprimands.

In home MRI scanner

[backslashdot]

I wonder if this could finally lead to an "in home" MRI scanner? If it costs under a thousand bucks and a person has a family history of cancer, why not invest in one?

Basically the device would be conveniently rolled over the bed once a month or so and scan. It will utilize advanced 3D image analysis to compare with last couple month's scan and see if you have any growing tumors. If so then you go get a proper scan done.

This will go well with the "in toilet" piss or shit tester that will tell you if you're going diabetic or may be developing some other medical conditions for example like kidney disease or cancer, etc..

Re:In home MRI scanner

[GrievousMistake]

Like other medical imaging technologies such as ultrasound, the images are medically pretty much worthless without a qualified operator to read them.
For ultrasound systems, a far cheaper technology, the cheapest systems seem to be around $10,000. And while I could see the geek appeal of messing around with ultrasounding various animate and inanimate objects, I am sure that if the price should reach sub-1000's, it would quickly become another weapon in the arsenal of hypochondriacs and hysteric pregnant women. Much of the same goes for MRIs.

Re:Oy! My payments...

[kmac06]

Well you could always go back to the 19th century and avoid hospitals if you don't like modern medical advances (which are quite expensive).

Re:Oy! My payments...

[Turn-X Alphonse]

Or you could have a sensible health care system where the rich can have giant breasts and the poor don't die from common and curable things.

You know, just a thought.

Re:Oy! My payments...

[guruevi]

I work at one of those MRI places and we do research and we are a non-profit. Although we're quite fully booked every day the use of the MRI still cost ~$500/hour. Basically the cost of operation divided by the number of scans done last year makes the price. Or do you think supercooling magnets to ~5K (that's Kelvin, convert to Celsius or Fahrenheit yourself) 24/7, the machine itself (~$3m) and support contract (~$125k) are paid for by the government not talking about the workstations to process the data and of course, my daily food?

About the article: those pictures are pretty unclear but it's promising.

Re:Nothing _that_ new...

[ceoyoyo]

Not quite. Higher gradients give you faster imaging. Higher fields give you better signal to noise. Better signal to noise can allow you to actually use those higher gradients without ending up with a big mess of noisy pixels.

If you've got lots of time you can achieve more or less any resolution you want with any field strength you like. The problem is, the darn patients keep getting impatient and moving.

The summary is pretty wildly inaccurate. This is actually a dual field scanner that uses a stronger field to polarize the sample and a weaker one for readout. It's pretty cool, but it's a niche thing... these guys want to do MEG scanning along with MRI and MEG is allergic to large magnetic fields. It won't be replacing the regular superconducting scanners and it won't be making cheap in-home scanners possible.

You can do nMR in the Earth's magnetic field if you want to. It's actually possible to set it up at home. I think someone was selling science kits for a while.

maybe a little bitter about this

[jpfed]

I was recently charged $3000 for a CT scan. Talking to an Indian coworker, I found out that a CT scan in his country would've cost less than $50. So I guess I could've flown out to India, gotten the CT, and flown back, for less money than getting the CT in America.

It's a good thing I did get that expensive modern medical advance in America, though, because of the high-quality analysis and follow-up I got from the clinic. In total, I got one sentence out of it- "Your intestines are a little constricted." I don't think they could provide that kind of advanced analysis in India with their cheap CT scans.

I guess I'm wondering- are modern medical advances really as expensive as we're led to believe they are in America?

Re:maybe a little bitter about this

[kannibal_klown]

To add insult to injury, apparently it's a growing trend to send the CT images electronically to India for a specialist to analyze.