F*ing magnets, how do they work?

October 4, 2012 12:22 PM

Magnetic resonance images of fruits and vegetables. And more MRI of more foods. Another 3D rendering of a broccoli MRI.

How does MRI work?
Just because I was curious, I found a tutorial for the Explanation of Gradient Echo vs. Spin Echo in MRI (Free reg. required to see animations.)
And for fun, here's some guys pushing a gas cylinder into an MRI.

posted by sararah (19 comments total)

3D Interactive Fruits and Veggies, from the same Inside Insides blog.
posted by sararah at 12:27 PM on October 4, 2012

Inside Insides previously.
posted by Nomyte at 12:43 PM on October 4, 2012 [1 favorite]

Very cool.
However, I couldn't help but imagine the many unimpressed, unfortunate patients here in Canada (where the wait time for an MRI is between 12-18 months), watching all of those vegetable images and thinking HURRY UP WITH THE FUCKING CUCUMBER WOULD YOU.
posted by chococat at 12:49 PM on October 4, 2012 [3 favorites]

Magnetic objects inside an MRI.
posted by Hollywood Upstairs Medical College at 1:02 PM on October 4, 2012 [7 favorites]

Very cool and all, but I'm gonna have to be the spoil sport and say that this doesn't seem like the most productive use of these expensive machines.
posted by The 10th Regiment of Foot at 1:04 PM on October 4, 2012 [2 favorites]

Some of those flower cross sections reminded me of Julia sets.
posted by aught at 1:09 PM on October 4, 2012 [1 favorite]

Ya'know, at the risk of being a derail starter, I can't help but ask: Why is the wait time so long for the machines? Are they being run 24/7? Do they need to cool down between scans? Is it a data-analysis logjam on the operator/doctor side of the equation? Are scans being prescribed where they aren't needed and thus overwhelming the hospitals that have them? Lack of certified operators? What?

I don't get it but I'm probably missing something obvious or just being naive.
posted by RolandOfEld at 1:10 PM on October 4, 2012

Man, I would love to get my hands on the DICOM data from these.
posted by Cat Pie Hurts at 1:10 PM on October 4, 2012 [2 favorites]

Neat pics...but I already know what the insides of vegetables look like.
posted by gnutron at 1:10 PM on October 4, 2012 [2 favorites]

Really enjoyed these. One thing that struck me after watching the video (the second link) is how much more interesting I found the video when it was purely an axial MRI, as opposed to a 3D MRI. I think it's because, with the 3D, you get a sense of the object in more or less the sense of how you already think of it. Whereas with the axial, you get cross section after cross section instead of the whole at once.
posted by marginaliana at 1:14 PM on October 4, 2012

The 3 T MRI at the Biomedical Imaging Center at Boston University where these images were acquired is a research instrument used for teaching MRI technicians and biomedical imaging. It is also used for doing research on a variety of human, animal and plant subjects, and developing new techniques to advance MRI in the clinical setting. I'd say that this is a very productive use of this expensive machine.
posted by sararah at 1:14 PM on October 4, 2012 [3 favorites]

"Very cool and all, but I'm gonna have to be the spoil sport and say that this doesn't seem like the most productive use of these expensive machines." - The 10th Regiment of Foot

"The 3 T MRI at the Biomedical Imaging Center at Boston University where these images were acquired is a research instrument used for teaching MRI technicians and biomedical imaging. It is also used for doing research on a variety of human, animal and plant subjects, and developing new techniques to advance MRI in the clinical setting. I'd say that this is a very productive use of this expensive machine." - sararah


Well that solves that.
posted by mitrieD at 1:17 PM on October 4, 2012 [1 favorite]

Also, when I was working at the UW radio-oncology clinic, I was told by the techs there that they use produce to calibrate the machines. Don't know if that's true or not.
posted by KathrynT at 1:42 PM on October 4, 2012

MRI scanners are calibrated using so-called phantoms, which are reference objects with known properties (usually fluid or gel-filled containers). By using a phantom, which has known and constant properties, we can assure that image intensity and "quality" remains consistent over time and comparable across machines. Some produce may be useful in certain scenarios (like pineapples and diffusion imaging that illustrates their internal fibrous structure), but I doubt any imaging centers seriously use anything other than a phantom. I'm pretty sure the Inside Insides guy just got his scans during the off hours at his facility. It's not like running the magnet versus not running it really makes a difference in the cost of maintaining it.
posted by Nomyte at 1:47 PM on October 4, 2012 [1 favorite]

Yeah, I was about to lay that down as Definitive Truth and then I remembered that I was a 20-year-old student helper whose dad worked in the cyclotron lab, and I realized there was a substantial chance they were pulling my leg.
posted by KathrynT at 2:01 PM on October 4, 2012

Vegetables you say? How about some meat MRI?
posted by Wet Spot at 6:08 PM on October 4, 2012 [1 favorite]

The dead salmon study linked in the previously thread recently was awarded an Ig Nobel prize. (There's been no 2012 Ig Nobel FPP, it would appear?)
posted by knile at 11:56 PM on October 4, 2012

These vegetables have almost no Kirlian aura. They mustn't be organic.
posted by obiwanwasabi at 1:12 AM on October 5, 2012

When I was a kid, I asked my parents for a microscope for my birthday.
"What would you look at under a microscope?" my mother asked, bewildered by her weird daughter.
"I'd like to see what's inside a leaf," I said.
"But that's obvious," said Mum.
"What?" I asked.
"More leaf."

I don't think I'll send these links to my mother. She probably already knows what's inside a vegetable.
posted by lollusc at 7:16 AM on October 5, 2012 [2 favorites]