[unholiness]

So, on the one hand, this is interesting! Reducing radiation from CT scans is a noble cause on its own. If on top of that it could make tomography cheaper and easier, you could imagine getting earlier detection of aneurisms, fibrosis, cirrhosis, thrombosis, stenosis, even plausibly cancerous masses (along with plenty of over-detection).

On the other hand, nothing here substantiates this promise. We've got a video render of what a hypothetical device could look like. It's probably more than nothing (they got exclusive license on these butterfly chips in 2025, and it's at least plausible that the best solution to the data bottleneck in an absurdly noisy system like this is real-time AI image processing)... But it's certainly less than something. It's a hype video that doesn't prove feasibility of anything, yet.

EDIT: This is all in reaction to the second video on the announcement post[0], which is much more informative than anything on the page currently linked.

[0]https://www.midjourney.com/medical/blogpost

[justaguyonline]

AI hype aside, this is one of those projects I'd like to know the open source stack of and the academic research behind. It's actually overlaps with an idea that started circling around in my head back when (deep) neural networks were the new hype cycle.

What's the relation between sensor density and resolution? If their array could give femtometer resolution, how much could you drop the density when you only needed to detect forearm muscle movements through the skim.

The way Ctl-labs was trying achieve the same results always seemed like it had fundamental physical limitations due to the nature of electromyography (to this software engineer...)

[A_D_E_P_T]

> femtometer resolution

The diameter of a carbon atom is 154 picometers. Nobody's going down into the femtos. And you're not going to get atomic resolution, either, because humans move around too much and things like scanning electron microscopes need very stationary samples. Even microscopic vibrations can blur the final image.

Which isn't to say that you couldn't get very good resolution...

[davrosthedalek]

Just for illustration: Gravitational wave detection is on the femtometer scale. The proton is about that size. We can measure these things, but the machines are, let's say, "big".

[Kotlopou]

Sigh...

LIGO detects length changes of 10^-18 m, or attometers, not femtometers, which are a thousand times longer. (https://www.ligo.caltech.edu/page/facts) But this does not matter at all, because this is not resolution of the body image, but the size of the vibration on the speaker. That's a technical data point that I don't see any reason to include in this presentation other than to cause this exact confusion.

The video looks in general like it's trying to impress by giving a lot of incidental information about how the device works while being very light on what it would be able to actually see -- e.g., it doesn't matter how many gigabytes your device collects if the resulting image is blurry.

Compare the website of LIGO (https://www.ligo.caltech.edu/page/facts), which also has a lot about the technical marvels (huge vacuum tubes! precision engineering!) but crucially includes the goal of this all.

[z7]

"I just tested my hand in a mini version of this scanner. Images that are higher quality than MRI, whole body captured in <1 minute, virtually free to run. This is going to change medicine."

https://x.com/SebastianCaliri/status/2067452733356122303

[KaiserPro]

I can't see how ultrasonic tomography can actually get anywhere near the resolution or penetrative depth that MRI can have.

Also The other thing I am unsure of is what the health effect of dumping you into an industrial scale ultrasonic cleaner. For example you can have doppler to measure blood flow in real time, but you can't do that for early pregnancy because of some health reason or other.

[Aromasin]

I help engineers design traditional scanners (Philips, GE, Siemens, etc). To be frank, this statement stinks like utter pig shit.

Some PE bro preaching miracles about a technology that I am sure they are in some way invested in making profit from does not convince me of it's legitimacy. My base instincts, from the unfortunate experience of working daily with PE bros, tell me the opposite in fact. It gives déjà vu of the Theranos hysteria.

[wasabi991011]

The X post is obviously biased, but I couldn't spot any obvious scientific mistakes in the actual announcement video.

Someone else linked to this preprint which seems related [1]. Would you take a look and say whether it seems legitimate?

[1] Whole Cross-Sectional Human Ultrasound Tomography” https://arxiv.org/pdf/2307.00110

[Aromasin]

The authors report explicitly state that the system's resolution does not match clinical CT or MRI. The elevational resolution is 15–25mm, meaning each slice is effectively a thick 2D section rather than the fine isotropic 3D volume MRI provides. MRI also delivers far richer soft-tissue contrast; this device produces only three contrast types (reflectivity, speed of sound, attenuation), and because it uses a low 1MHz frequency, the reflection images come primarily from tissue boundaries rather than from internal tissue texture.

I could see this being valuable for adipose tissue mapping or fatty-liver monitoring at a large scale, as the machines would be significantly cheaper, but this isn't some revolutionary magic bullet like the Twitter post is insinuating.

[femto]

As someone in the medical imaging field, are you aware of anyone working on passive sonar for medical imaging? I'm curious, as it's something that I've always thought would be fun to work on.

[Aromasin]

For context I'm in engineering consultancy, so by no means an expert but I probably have enough experience to be on the other side of the Kruger curve dip.

Passive sonar in the naval sense means listening only, not emitting. Do you mean imaging that relies solely on acoustic energy already present and emitted by the body? If so, then generally no. You have two types of "passive" imaging. First would be hardware-passive, as in MR elastography (most common), where the patient wears a transducer pad, and vibration is actively generated by a driver. You've then got algorithmically-passive, which is more analogue to passive sonar, reconstructing tissue stiffness from ambient broadband vibration without the emitted probing pulse, but that is very much entirely academic. I guess the question would be, why is it worth pursuing when you have something like optical coherence elastography (OCE) for non-invasive profiling. Doing it using noisy ultrasound method becomes redundant. There are other methods, but the outcome is the same.

Generally (this is true for all systems, not just humans) you need to induce energy into it to more effectively measure it's output. Think of it like a bell - if I want to hear the note it produces, it's much easier to hear what this is if I ring it with a hammer. Granted, it will be "passively" resonating to a point where, with a sensitive enough sensor, I could probably pick up the output without the hammer - but that is a pointless problem to solve. I could hit a bell with a soft hammer a million times over without causing damage to it. The lifetime of the person hitting it with a hammer is far shorter than the accumulative damage to the bell before it breaks. The same is true for humans. You could effectively run a very low-energy, 60Hz vibration through a person (which is how the pads work) for multiple lifetimes before it would cause significant damage, so there comes little point in solving that problem. As such, true "passive" imaging is functionally pointless if your outcome is "safely image a patient". You're overengineering your solution to solve a problem that is only relevant if your patient was planning on living for 1000+ years.

[femto]

I'm thinking passive, as in using only acoustic energy that is already present. Partly it's about minimising irradiation, which you are saying is not a concern.

The more interesting aspect to me is whether the ambient emissions carry useful information. I recall a paper from a few years ago about yeast emitting sounds (mechanical vibrations) in the kHz range. I guess the question I am interested in is "what does life sound like at the cellular level?" Maybe it is silent, but my gut says it's probably making some sound, even if it's very weak. The questions are then along the lines of "What does a healthy cell sound like?", "Do different cells make different sounds?", "Do sick cells make different sounds to healthy cells?". It's absolute pie-in-the-sky stuff, but it would be fascinating to know.

My background is radio communications (with some acoustics) and radio comms has a history of things that used to be considered random noise turning out to be useful signal as processing has developed to the point where signals can be resolved. For example, multipath reflections used to be considered just random interference until the invention of MIMO, at which point they became useful signals and comms systems took a leap forward.

[Pay08]

What does PE mean?

[oinoom]

private equity

[cornstalks]

> Reducing radiation from CT scans is a noble cause on its own

Is it? Linear No Threshold has largely been rejected at this point. https://jnm.snmjournals.org/content/early/2024/06/21/jnumed....

[adastra22]

We have no evidence in favor of the linear no threshold model. That is not the same as saying that we have evidence against it.

[haldujai]

There is some evidence for hormesis - but yes no model is proven right now. LNT is the most conservative model and part of why it sticks around.

A good primer: https://pmc.ncbi.nlm.nih.gov/articles/PMC2477686/

[looofooo0]

LNT does also damage, as people refusing necessary CT scans or countries switching of nuclear power because of fear.

[arcticbull]

Sure but we don’t prove negatives for a reason - it’s impossible. We assume the null hypothesis.

[unholiness]

LNT is the null hypothesis. No one disagrees a linear model fits the data very well in high doses. If you want to argue that model doesn't work in low doses, you need a model with more parameters and sufficient data to fit it. The issue is that, at these low doses we want to differentiate, we're also looking at effect sizes that are hard to separate from noise, and sampling biases that are hard to erase. There's still lively and ongoing debate.

[looofooo0]

Well problem is that humans are so noisy through lifestyle, enviroment and genes that any proof for either is really hard.

[unholiness]

Another problem is that there haven't been natural experiments in low dose exposures the way there unfortunately have been for high dose exposures.

[dooglius]

Your link does not support, and in fact refutes, your claim

[KaiserPro]

Weekly CTs are going to give you cancer

[kibibu]

I'm not putting my head under. How do we know this won't cause aneurysms? Damage eyes and ears? Getting a medical device approved takes time because of concerns like this.

[autoexec]

It might not actually cause harm or strange effects to people's bodies, but I'd certainly feel better if it was tested and used by doctors in a hospital and not some "spa" since those tend to be poorly regulated and where all kinds of quackery takes place (https://www.aafp.org/afp/afp-community-blog/med-spa-industry...).

The safety of the device itself is a concern, but so is the trustworthiness of the output. Midjourney already has some very questionable history with medical imagery (like this totally legit image of rat testicles published in "Frontiers in Cell and Developmental Biology" https://upload.wikimedia.org/wikipedia/commons/c/cc/AI_gener...)

[Levitz]

>Midjourney already has some very questionable history with medical imagery (like this totally legit image of rat testicles published in "Frontiers in Cell and Developmental Biology" https://upload.wikimedia.org/wikipedia/commons/c/cc/AI_gener...)

I don't think "someone used their tool to produce a silly result and used it" qualifies as Midjourney having questionable history at all.

[ElFitz]

> The safety of the device itself is a concern, but so is the trustworthiness of the output.

And the safety of the data as well. Am I supposed to entrust full body scans to a startup?

[zythyx]

From my understanding of the post, the waves that are created are smaller than light waves, and there's no evidence that light waves, sound waves or sub-sonic waves have any aneurysm-causing effects.

(I researched more and found in the video a value) The waves are 50 nanometres, and this is basically the equivalent of having a full body ultrasound. We've been doing baby ultrasounds for decades with no ill effects, so I can't imagine this being different

[kibibu]

Ultrasonic wavelengths are orders of magnitude longer than light.

[mNovak]

We already ultrasound babies in the womb, so one would hope this has been studied.

[reverius42]

Before ultrasound, they used to x-ray pregnant women to see the fetus. At that time, someone might have said "one would hope this has been studied"... unfortunately that practice went on for about 60 years before being stopped in the late 1950s.

Side note: kinda crazy they had medical x-rays in the 1890s. X-Ray imaging was discovered in 1985 and used clinically within 2 years.

But I do agree with your point, these days, I hope we're better about studying the potential dangers of current technologies we use.

[rdl]

We also used to x-ray people for shoe fitting/for lulz.

https://en.wikipedia.org/wiki/Shoe-fitting_fluoroscope

[toasty228]

We also put lead in paint and gas because why the fuck not? Asbestos pretty much everywhere because it was a miracle material, etc. for decades, and we're still paying the price

[krick]

> But I do agree with your point, these days, I hope we're better about studying the potential dangers of current technologies we use.

Sorry, but this is just pure "Gell-Mann amnesia effect" vibe to me. I mean, you've just brought up a perfect example yourself! What kind of mental gymnastics does it take to still hope that this time it's not like that?

I don't wanna start the whole "vaccines cause autism" thing and whatnot, and surely you shouldn't avoid ultrasound just because of irrational fear of some yet undiscovered side-effects, but it's really amazing, how people tell fun stories about how common was the narrative about major war being very unlikely in "modern days" (because who would dare to do that with this kind of technology!) right before WW1, and then conclude with firmly believing that these days (after WW2) it sure won't happen, because humans are not that dumb. And my point is, that perhaps it indeed might have been a bit less likely, if people didn't believe that it is so unlikely to keep stepping on the same rake.

[carlosdp]

that's not a video render of a hypothetical device, that's a real video of the real working device, fwiw

[mrandish]

> the real working device

Could you expand on the term "working"? Do you mean like "working to slowly lower a person into water while videos of animated Figma UIs play back on a monitor?" Or do you mean some crazy kind of "working", like "the ring of devices we see are scanning the organs of the woman we see and the images appearing on the monitor are those just-captured organ scans?"

[datadrivenangel]

It's just a render? Where's the video?

[roarcher]

The first video appears to be real. Who knows if it's a working prototype or just a mockup, but the fact that it's held together by C-clamps and other stuff you could get at Home Depot makes me lean towards the former. If it was purely for marketing they'd probably make it look more polished.

[moffkalast]

> The first video appears to be real

The video is clearly from Midjourney /s

[bastawhiz]

The first video has the actual device (whether it's functioning or not) and the second video is a render.

[camillomiller]

This reeks of peak bubble, it’s ok say that.