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A low-cost and shielding-free ultra-low-field brain MRI scanner

nature.com

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Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#31

Post by jacquesm »

ortusdux wrote: post #19
l33tman wrote: post #8

Earlier quoted context omitted.

This project doesn't use AI to improve the image, they use it to estimate the EMI noise from the surroundings. So they're not "filling in the gaps" in the actual resulting 3D voxel volume with fantasy voxels (which I hope will never ever fly in a clinical setting). "To tackle the EMI signals from the external environments and internal low-cost electronics during scanning, we developed a deep learning driven EMI cance…

I'm glad that this is the approach that they are taking. There have been plenty of issues with fMRI false positives due to misconfigured software. The most famous would probably be the IG Nobel winning study that detected brain activity in a store-bought salmon: https://blogs.scientificamerican.com/scicurious-brain/ignobe... https://www.discovermagazine.com/mind/fmri-gets-slap-in-the-... Later studies called into que…

> The most famous would probably be the IG Nobel winning study that detected brain activity in a store-bought salmon:

A store-bought dead salmon.

I am assuming that most salmons bought in stores are dead but that particular detail is rather relevant here.

Also that had me laughing, what a great move.

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#32

Post by TheJoeMan »

lostlogin wrote: post #4

The images are better that I expected. The ‘FLAIR like’ image is not particularly FLAIR like. FLAIR are nicer to look at when fat saturated (not everyone agrees with that), but that’s probably not feasible at that field strength and adding scan time would be a problem on these long sequences. Voxel sizes of 2x2x10 are pretty terrible resolution, but if the alternative is nothing, I guess that’s ok. The static field i…

You know, sometimes all you need is “do I have a baseball sized tumor or not”.

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#34

Post by a-dub »

l33tman wrote: post #8
a-dub wrote: post #5

woah. woah. woah. hold on a second here... are we comfortable enough with understanding all of the behavior of deep learning models to where we can confidently put them in the pipeline for diagnostic clinical imaging? i'm okay with using them for image analysis, but denoising and other image production tasks seems dangerous. how do you know what you're looking at is real as opposed to something that just looks convin…

This project doesn't use AI to improve the image, they use it to estimate the EMI noise from the surroundings. So they're not "filling in the gaps" in the actual resulting 3D voxel volume with fantasy voxels (which I hope will never ever fly in a clinical setting). "To tackle the EMI signals from the external environments and internal low-cost electronics during scanning, we developed a deep learning driven EMI cance…

the primary innovation is using deep learning to denoise the signal and the cost savings derived from being able to use a noisier signal.

whether you call it "SnR improvement" or "additive noise cancellation", it is undeniably adulteration of the signal.

looking at the supplementary information, it looks like this paper was reviewed by mr-physicists. i think it also should have been reviewed by ml experts as well.

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#36

Post by gnatman »

ratg13 wrote: post #33

When we say "low-cost", just how low cost are we talking here? I skimmed through the article, but still didn't comprehend how much something like this might actually cost.

Towards the bottom: "Such scanner can be made low cost to manufacture, maintain and operate. For quantity production, we estimate hardware material costs under USD20K."

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#37

Post by AnimalMuppet »

TheJoeMan wrote: post #32
lostlogin wrote: post #4

The images are better that I expected. The ‘FLAIR like’ image is not particularly FLAIR like. FLAIR are nicer to look at when fat saturated (not everyone agrees with that), but that’s probably not feasible at that field strength and adding scan time would be a problem on these long sequences. Voxel sizes of 2x2x10 are pretty terrible resolution, but if the alternative is nothing, I guess that’s ok. The static field i…

You know, sometimes all you need is “do I have a baseball sized tumor or not”.

But if the answer is "yes", the next question is "do I also have pinhead-sized metastases, and if so, where?"

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#38

Post by nichos44 »

ortusdux wrote: post #19
l33tman wrote: post #8

Earlier quoted context omitted.

This project doesn't use AI to improve the image, they use it to estimate the EMI noise from the surroundings. So they're not "filling in the gaps" in the actual resulting 3D voxel volume with fantasy voxels (which I hope will never ever fly in a clinical setting). "To tackle the EMI signals from the external environments and internal low-cost electronics during scanning, we developed a deep learning driven EMI cance…

I'm glad that this is the approach that they are taking. There have been plenty of issues with fMRI false positives due to misconfigured software. The most famous would probably be the IG Nobel winning study that detected brain activity in a store-bought salmon: https://blogs.scientificamerican.com/scicurious-brain/ignobe... https://www.discovermagazine.com/mind/fmri-gets-slap-in-the-... Later studies called into que…

Those false positives are because fmri runs countless statistical tests and the earlier "misconfigured software" wasn't running stringent enough multiple comparisons corrections. Basically the same issue in the classic "jelly bean causes acne" xkcd (https://xkcd.com/882/). The exact number depends on voxel size, temporal resolution, and experimental condition but is somewhere close to tens of thousands of tests.

The "images" that are presented in fMRI studies and that contain false positives are representing results of statistical tests (t-values, and f-values after correction) not the contents of voxels. So the false positive rate of an fMRI has very little to do with the accuracy of a voxel's content in a structural MRI.

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#39

Post by ska »

devwastaken wrote: post #35

How does this fare against patents? Isn't pretty much everything to do with the actual implementation of an MRI patented and copyrighted in some way to prevent anyone else from entering the game?

The basic patents all expired ages ago. There are details patented by everyone, but there is a lot of FTO.

The real barrier to entry is cost. Building out a permanent magnet system like this is likely an order or two cheaper though.

Re: A low-cost and shielding-free ultra-low-field brain MRI scanner

#40

Post by ska »

TheJoeMan wrote: post #32
lostlogin wrote: post #4

The images are better that I expected. The ‘FLAIR like’ image is not particularly FLAIR like. FLAIR are nicer to look at when fat saturated (not everyone agrees with that), but that’s probably not feasible at that field strength and adding scan time would be a problem on these long sequences. Voxel sizes of 2x2x10 are pretty terrible resolution, but if the alternative is nothing, I guess that’s ok. The static field i…

You know, sometimes all you need is “do I have a baseball sized tumor or not”.

In that case, likely you found it before anyone asked for an MRI.
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