Ultrasound imaging of the brain | Hacker News Reader

Ultrasound imaging of the brain

alephneuro.com

324 pointsrossant126 comments

Even low-dose ultrasound (what they use on pregnant woman) results in ultrastructural changes in brains [0], specifically at the nodes of Ranvier (the gaps between myelin along axons). See also [1] for a review.

[0] Ellisman MH, Palmer DE, André MP (1987), "Diagnostic levels of ultrasound may disrupt myelination," Experimental Neurology 98:78–92 https://pubmed.ncbi.nlm.nih.gov/3308504/

[1] Quarato, C.M.I., Lacedonia, D., Salvemini, M., Tuccari, G., Mastrodonato, G., Villani, R., Fiore, L.A., Scioscia, G., Mirijello, A., Saponara, A. and Sperandeo, M., 2023. A review on biological effects of ultrasounds: key messages for clinicians. Diagnostics, 13(5), p.855. https://pmc.ncbi.nlm.nih.gov/articles/PMC10001275/

All sound is vibration, so everything is affected by sound at some point as the vibrations propagate through and physically move around materials. Humans can hear because the audible frequency range moves receptors in human inner ears, and as you can imagine this isn't local to the ear, the whole brain will be affected (but biology has accounted for this). If you knock on wood that sound is audible in many frequencies--below human audible, audible and also above human audible (what we call 'ultrasound'). What is more dangerous generally is sustained noise at any frequency; lower frequency + high amplitude is one of the most harmful as that can physically push you.

>sustained noise at any frequency is dangerous

is this your conclusion? are there any studies you can link? thanks.

Interesting, if ultrasound effects the brain, then maybe specific pattern could be used to non-destructively stimulate it?

There's Ultrasound DBS Deep Brain Stimulation.

/? ultrasound brain stimulation: https://www.google.com/search?q=ultrasound+brain+stimulation

There's ultrasound for Alzheimer's, which may not be about Amyloid Tau;

"Improving Cognition Without Clearing Amyloid: Effects of Tau and Ultrasound Neuromodulation" (2024) https://journals.sagepub.com/doi/10.3233/JAD-240616 ... https://scholar.google.com/scholar?cites=1746486614029868186...

Also, Beta-Cyclodextrin apparently reverses atherosclerosis in the body and brain - by "absorbing" sugar-alcohol FWIU - and it's already approved but we don't know what dose is low enough to be safe.

Cool work and proof of concept, and very excited to see where this goes. However, I do think there is enough exaggeration and missing information here that it warrants some critical appraisal. What's really missing is a comparison and validation with any existing medical imaging tech. Whole brain, contrast-free neurovascular imaging is essentially solved with MRI, why not run a scan and compare? Ultrasound is of course portable and less expensive, but MRIs are actually widely available in most cities at reasonable cost for medical workflows, and low-field brain MRI is addressing the portability and cost issues to some extent. I guess they are pitching this as a wearable "telepathy" device, which I think appropriately differentiates their product, but of course, this wording also invokes a framing that "you won't / don't need to know how it works," which invites skepticism and a higher bar for validation in my view.

most cities where?

Here are OECD and WHO reports on regional availability of MRI:

https://www.oecd.org/en/publications/health-at-a-glance-2025...

https://www.who.int/data/gho/data/indicators/indicator-detai...

Africa, Central & South America are clearly underserved, perhaps a good opportunity for ultrasound and low-field MRI

"MRIs are actually widely available in most cities at reasonable cost" - I live in one of those first-world countries, and our citizens regularly wait many months if not over a year to get a single MRI scan. Yes, it's not just an issue of the MRI but the entire medical system, but the point still stands. Were there machines that were one or more orders of magnitude cheaper and simpler to run - I think we would see a marked increase in availability.

I agree on your ground-truth desire, and I would hope they've done a lot of that to validate what we see here.

I completely agree that's an issue, although more of an economic / public health policy issue than a technical one. There are low field MRI systems, such as the one made by Hyperfine that are, like you say, an order of magnitude cheaper and simpler to run. We should have these everywhere, IMO

https://www.hyperfinemri.com/

MRIs are fundamentally expensive. Yes we can bring the price down a bit, and we can set more money aside for them, but they’ll always be limited by their price.

Even if this technique is much worse (I can certainly believe it is) the price might allow uses that would never be practical with MRI even with the best financial support. For example, ultrasound might be viable for use in GPs or small medical facilities which could never dream of justifying an MRI machine.

Yes totally, and ultrasound already does wonders in that regard. It's a good strategy to focus on the specific use cases that match the strengths of the tech. I think MRI will be useful in validating and mapping out those cases.

Why would they remain fundamentally expensive? It is a fixed machine (so eventually you recoup the investment) and running consumes nothing other than electricity and a paper gown. MRIs cost under $200 in Japan.

> $200

This makes more sense than the comment elsewhere here that says $50.

My guess: It would be a basic scan with minimal sequences and low quality at that price.

Is $200 close to what it costs the hospital, or after subsidies?

$200 is the cost for the hospital, they "resell" it for $750-1500 mostly paid by insurance

With insurance in the US they’re $750 each… As in elbow and wrist on the same arm count separately…

The methods described in the main article refer specifically to neurovascular imaging. In order to have a higher resolution, they’re making use of microbubbles (which need to be prepared and injected just prior to imaging).

There is no world where vascular imaging with a methodology like this is better than what I can do today in a GP clinic with a handheld GE or butterfly (or similar) US probe for anything that matters:

- for dvts and thrombus I can already image them

- if it’s in the brain the last thing that is useful for you to do is fuck around in a small clinic when you should be getting to a major tertiary centre as soon as possible

They are claiming to want to detect CTE which normally is only diagnosable in an autopsy, I thought. Can current MRI do that? Right now we get former NFL players offing themselves with gunshots to the chest, intentionally leaving the brain intact for postmortem scanning, so posterity can figure out what was wrong with them. It's painful to think about.

My impression isn’t that they are trying to improve CTE imaging (did it say that in the article?!) but somehow approach the resolution of being able to run the blood flow data through a black box so they can demonstrate what the occipital cortex is processing. I mean, that’s literally the first part of the article?

Can MRI/CT demonstrate CTE.

Well, like a lot of things which as alzheimers, that is still a pathological diagnosis for the most part, to the best of my knowledge (not post mortem scanning but out some brain tissue on a slide), but this belies the general fact that getting the tissue diagnosis is really not that important to anyone except a pedant, because yes MRI will show changes in grey/white matter differentiation and size compared to age and sex weighted cohort; and CT will show similar; and in fact it is the history and examination that practically matter to both the patients and their family.

So while it’s nice to have a totally 100% bulletproof ‘diagnosis’ for labelling purposes, practically on history and exam it’s not going to change how they are managed or what they and their family do say to day; given that both CTE and basically any of the dementias don’t have any treatment associated with them, and the current neuro imaging we have can deliver much higher resolution than what this is promising anyway (I mean even CT angio, and it’s not using ‘advanced imaging processes’ to create data out of noise)

Many months to a year for an MRI? Wow, in the USA, we can get MRI's the same day or at worst case, week. It's been that way for a decade or more.

> Wow, in the USA, we can get MRI's the same day or at worst case, week.

You can. And the cost is higher than almost anywhere on earth.

You can get them quickly in most places with a publically funded healthcare system, it’s just that a priority patient is very very sick and you never want to be that person.

Scarcity demands some means of rationing out the product. Setting higher prices is one means of doing this, so only those with some means of paying can get it. Another approach is via wait times, where only those who can wait and afford the time penalty can get it. There are other variations, but there's no such thing as a free lunch.

The scarcity comes from waiting to get preapproval from your physician and health insurance. If you are willing to pay out of pocket, there are many private MRI clinics that will scan you to your heart's content, as quickly as you want, as long as the payment clears.

Granted, anything you find in that reading won't be accepted by your physician or insurance company, so it's more of a checkup for you and you alone. And most scans will find something anomalous. We're all asymmetrical and lumpy. so take that as you will.

> anything you find in that reading won't be accepted by your physician or insurance company,

Surely that it isn't the norm? Where do you live that the (I assume government run) health system dismisses evidence when its collection wasn't sanctioned by official channels?

They are mistaken. I am a practicing radiologist in the US. We regularly work-up findings from private pay whole body screening MRIs and the workups are covered by insurance.

The scarcity comes from there only being a finite number of the devices.

But I was really speaking more broadly, about healthcare in general. There are only so many doctors, so many MRIs, so many heart surgeons, so many this or that. Giving everyone a bunch of extra money so they could pay the current prices doesn't do anything to address the scarcity, so everyone flush with those subsidies will just bid up the prices - which is exactly what happened.

Your country has decided to ration MRIs.

Here in Australia, it is a one to two day wait for a MRI. Costs 240 AUD, (160 USD ) for a 1.5 Tesla MRI and AUD 400 for a 3 Tesla MRI just up the road.

And if I mark the request Urgent, I can send a patient 5 minutes up the road and have it done within the hour.

Are you in the UK ? I know that the UK health system has effectively collapsed, due to that country's poverty and chaos.

Even in Sudan the waiting time is less than in your country:

"Due to the ongoing conflict in Sudan, healthcare infrastructure and diagnostic imaging services have faced severe disruptions, with wait times for an MRI now extending from several weeks to months"

As an Australian I've had specialists say improved resolution is leading to over diagnosis and over presentation risks. An argument in the margins and one which loses its force as we learn to interpret finer grained imaging better, do you see this as a valid critique? (The case I last heard of was a future blockage/calcification risk in the carotid which the specialist said was way way too young to act on and would not have been noted before imaging improved)

> do you see this as a valid critique?

It's a valid point to raise, and a point critical of "boutique" medicine practices specialising in insecurities of the rich.

In a nutshell our flesh is rarely homogenous, more often tarnished by odd blemishes and gnarly growths that often amount to naught.

Experienced work a day doctors appreciate seeing odd lumps earlier but refrain from taking any action until some threshold is crossed "for fear of doing greater harm" - the knives that cut things out, the concoctions that burn things away often come with side effects.

Contrasting that, the Lamborghini doctors actively self promoting their genius on 60 Minutes and other Australian paid journaltising media - they're up for any excuse to charge for an "essential procedure" (pinky promise no failures).

Improved resolution is sometimes irrelevant, but the advent of high Telsa scans has improved multiple sclerosis diagnosis and has led to revision of the MacDonald criteria. Particularly the addition of of the central vein sign as an imaging marker and the addition of the paramagnetic rim lesion https://radiopaedia.org/articles/mcdonald-diagnostic-criteri...

As for incidentally found abnormalities, acting on every abnormality is AI level dumb. One has to use Bayesian reasoning and consider risk, context and the likelihood of the lesion being real.

This is in Canada. Our healthcare problems are both well known and well documented, but also strongly resistant to being solved. I do wish we had a system as efficient as what you describe. I’ve personally been on the receiving end of this nonsense. And it is actively costing lives every year. That’s just the tip of the iceberg of course.

No joke, it’s actually a lot easier to schedule an assisted suicide than it is to receive proper treatment in a large number of cases.

> MRIs are actually widely available in most cities at reasonable cost

Typical wait time for an MRI in Canada is 2 months.

Yes, that is a economic & public health policy problem that really needs to be solved. We can look to Japan as example of what's possible, they have invested in nearly twice the number of scanners per capita of Canada, and they can get same-day MRIs for $50, roughly speaking.

> they can get same-day MRIs for $50

I’d like to see a breakdown on how they do that. Staffing alone is a multiple of that.

From what I know, seems like a mix of medical price fixing by the gov't, adoption of lower cost hardware, and universal healthcare. There's apparently less bureaucracy, perhaps because there is no need for negotiation at every step of the process?

There are big costs. The hardware, the facility (RF cage and chillers), power, water, staff, RIS/PACS etc etc.

I can’t see how you can do it for $50. Does the ‘universal healthcare’ bit mean that the government is paying most the bill and it’s $50 out of pocket?

Yes, $50 was a rough out-of-pocket estimate, the amortized cost per scan for operation alone is probably on the order of hundreds of dollars per scan, assuming high utilization.

One funny thing about MRIs is the magnet is always on, so there could be some clever ways to reduce costs running them after hours.

> there could be some clever ways to reduce costs running them after hours.

It seems like a dedicated round the clock facility housing at least dozens of MRI machines ought to offer significant economies of scale. I wonder if I'm wrong about that or if there's some other reason we don't see this approach taken by governments.

The staffing costs then skyrocket. 1.5x or double time. However, the main obstacle is a lack of staff. Good staff are hard to find and worth what they cost. And they usually don't want to work out of hours. The economies of scale are interesting. Eg PACS/RIS cost very little more when you increase scans done, and rent is a fixed cost. The best thing that happens are you increase scanners at a the management of no-shows. Patients fail to turn up regularly (a 'did not arrive', DNA). With more imaging going on, you just grab the next available patient, the gap ends up later on, then you make a new booking. The record at my site is 6 DNAs and no slots missed. I run a small MRI service.

> 1.5x or double time.

Is the premium really that large for the night shift at (for example) a hospital? But even if you can't do 24/7 presumably there are physicians and technicians who would be willing to do either early morning or late evening without demanding much of a premium.

A massive daytime only facility should at least enjoy reduced capex and maintenance burdens if they have enough machines in one place. Less duplicated infrastructure and everything closer at hand.

Although if as you say even a small service can paper over 6 DNAs without missing a slot then maybe there isn't all that much to be gained here.

I’ve just checked the contract for the largest employer of techs (in New Zealand) and they only get 1.25X for night shifts. This is the rate at public hospitals. Private employers pay more and the penal rates are more aggressive - due in part to none of us wanting nights or weekends worked.

However that’s a bit meaningless as night shifts don’t exist. MRI is run as an oncall service and only acute scans are done at night - good luck getting a consultant to come in for anything less.

There are staff who like early starts (6am) and a smaller number who like to finish a bit later 6-9pm).

Techs are lucky enough to be in demand and if an employer pushes too hard, they’ll go somewhere that’s a better fit.

We only site 2 MRs next to each other, so savings are going to be minimal but we do see staffing advantages and less downtime. Coils scan swap between machines, one chiller can supply both MR scanners (just… be careful).

https://apex.org.nz/wp-content/uploads/2026/03/Te-Whatu-Ora-...

Romania: for a head MRI on demand - not more than a few days and less than 400 Euros.

That’s more believable than $50, and isn’t out of whack with what’s achievable where I am (New Zealand).

Depends for what reason. I trained in Canada. Studies are triaged priority 1 through 4 in most provinces. Nowhere in Canada is a high priority MRI waiting 2 months.

As the article says, their ultrasound machine costs about as much as a smartphone. It’s about $4000.

An MRI machine costs roughly 1000x as much.

> An MRI machine costs roughly 1000x as much.

The running costs are also eye watering.

Not your point, but… Do smartphones cost $4000 dollars now??

No but that's the order of magnitude. The high end is commonly a bit over $1k.

The foldables are around 2k

A $1m machine with (say) $100k of annual operating costs with a 10-year lifespan. Assume low cost of capital, call it $200k/year for those 10 years.

The machine itself covers its cost at only ~84 monthly scans @ $200 each. That says to locate near population centers where the demand exceeds 84 scans. At the global mean of scans/population, said "population centers" only need to be about 15k residents.

Labor costs + junk fees make them appear expensive.

> The bubbles themselves are pockets of sulfur hexafluoride encapsulated in lipid shells.

The high resolution images were generated by injecting sparse bubbles of this contrast agent. How sparse are they? Is the image we see a stacked set of many bubbles over time composited together?

Their aspirations at the end of doing this without the bubbles are great, but there’s a big “now draw the rest of the owl” energy around that leap. The first technique relies entirely on the bubbles, but they provide no explanation for how they think this could be achievable without the bubbles other than vaguely saying that technology is advancing.

re: imaging red blood cells

The super-resolution trick as they’ve done it is highly reliant on the sparseness of the bubbles. If you imagine a point or a very sparse set of points at low resolution, you can fit for the locations of those points even though you don’t see them clearly. This is a common technique in radio astronomy and (I assume although I don’t have personal knowledge) astrometry, and compressed sensing was an extremely hot field a while back.

But RBCs are weird squishy things, and they fill the bloodstream quite densely, and ChatGPT estimates that they’re spaced about 20µm apart and that, when confined to a capillary, they’re about 7µm long. (And that sounds at least plausibly correct to me.)

So, even ignoring the much worse scattering properties of RBCs, they not nearly as sparse. You mostly lose a whole dimension of sparseness and up trying to resolve the entire capillary. Which seems possible but much harder. Unfortunately, brain capillaries are about 40µm apart, so the result might be a mess.

The article did not say what wavelength they’re using or what their native (wavelength/2) resolution is.

I’m a complete layman to this field, but what the article did say was they’re hopeful that AI/ML can help develop a model that can pull out information such as the scattering caused by RBCs (which is present in the large volume of data gathered by the probe but is too weak to be used for manual techniques) and turn that into meaningful visuals. That’s gonna require a ton of data and that is exactly what they are trying to gather now with what they have built so far.

Showing us a technique that is entirely reliant on sparseness and then saying they hope to employ it on something that isn’t sparse at all (blood cells) does feel misleading.

I’m filing this in the category of technologies I wish could be true, but for which no plausible path to overcoming the obvious limitations has been provided.

From the bubble center plot, I'm guessing that the bubbles are separated on average about a few mm apart? Taking the other comment's guess at face value, you're going from about 2 mm to 20 um, so 2 orders of magnitude. Air (technically SF6 in the article) and water (RBC is close enough) have acoustic impedances that differ by 3.5 orders of magnitude.

My assumptions here are *extremely generous*, i.e. favorable to the "oh, we'll just make it work with natural contrast", and even then, they can't hand wave 5-6 orders of magnitude of improvement. Furthermore, because of the use of super resolution, I'm guessing there's some exponential factor in there, i.e. double the density of bubbles/tracking points past some critical limit, then you need 8x the data to reconstruct things.

> From the bubble center plot, I'm guessing that the bubbles are separated on average about a few mm apart?

The page is vague so I can't tell. I think the images they're showing are actually a composite of many bubbles tracked through the vasculature.

They say this:

> As bubbles flow through the vasculature, we accumulate millions of these positions and stack them into a single image with detail finer than the wavelength.

And the rendering showing the bubble centers they're tracking only shows a few small points moving at a time.

I think that the amazing animation they produced at the top is actually a composite of many different trackings, not an actual representation of what they capture in real-time.

As another way to estimate this, here’s a data sheet for some microbubbles:

https://pdf.benchchem.com/1673/Application_Notes_and_Protoco...

So 1-5e8 bubbles per mL, and let’s suppose you inject 5mL. (I have no idea what the human dose is, but that’s what’s in this particular kit.)

You apparently have 5e9 or so RBCs per mL of blood:

https://en.wikipedia.org/wiki/Complete_blood_count

You have about 5L of blood, so that’s three orders of magnitude more volume than the contrast, and RBCs are 10x-50x as concentrated as the microbubbles in the syringe, so about 4 orders of magnitude concentration difference.

It’s basically changing this from a 0D problem to a 1D problem.

I believe this is also used for regular astronomy with dithering

The imaging stuff is cool but the homepage is making me wince.

There's a compelling argument to be made that the level of detail in "mind reading" they are gesturing at is plain unrecoverable with hemodynamics. There's an irreversible loss of dimensions that occurs the instant you start recording blood instead of spikes on the neural circuits themselves, and it's not at all clear that what a VC reading the words "telepathy" is imagining even survives that transformation.

What you have is food delivery data for a neighborhood, this can tell you a surprising amount, including when they might throw a party. What it can't tell you, however, is who wore the best outfit and what was talked about over dinner. The information simply does not survive across the interface.

There is a spectacular canyon between "informed interpretation" and "mind reading"

Meta is also going at it [0], which inevitably makes me ponder some orwellian questions for the near future:

If I bring my pet mouse to the cinema and my friend scans the movie back using his apple ifmri does the DRM still holds or will the mouses be DRM locked? Will my iris suffice for booting my computer or would I need to press accept all brainwave cookies? Can I email my local Flock representative to install a new Brain Pole in my neighborhood? I saw a bunch of dark thoughted young males around and my amazon think camera says the probability of missing packages increased.

[0]https://ai.meta.com/blog/tribe-v2-brain-predictive-foundatio...

Certainly the thing of sci-fi nightmares, but not practical.

All of these imaging techniques are very involved. Ultrasound requires direct contact and this technique only works with a long IV infusion of bubbles. fMRI isn’t going to be a portable device that you can point at something for many reasons.

The connection to what you’re thinking is more sci-fi than reality. This technique could theoretically see some changes in blood flow to different regions, but what would that mean? Is the patient having anxiety, or are they just nervous about the IV injecting bubbles into them to travel to their brain and the machine attached to their head?

The current state of the world, where we have insane and ubiquitous surveillance tech but our packages are nevertheless being constantly stolen (with the thieves "caught" under said surveillance but with no one bothering to enforce it), is certainly an interesting one.

I wonder what Orwell would have thought.

The surveillance is not about protecting you or your property; I'd argue it never has been. It's about protecting those in power and entrenching the power they wield.

Every few years one of these ultrasound companies comes around and promising to revolutionize medical imaging and nothing ever comes of it. Anyone remember https://www.openwater.health? The same ideas are in a perpetual state of being reinvented and part of me thinks its just a hustle for the MIT Media Lab/Stanford Imaging grads to give them something to do.

The tell is "super resolution", "brain computer interface" and "mixed modality" -- adding some contrast agent here, or maybe an IR light source.

It turns out the nyquist limit, diffraction and physics are real things.

It doesn't work until it does.

The same thing has been said about robotics, AI, space travel, etc. etc.

I'm not saying this is the way, and I have significant questions of understanding thought based on reading brain activity, but I wouldn't put down the entire ultrasound field.

It doesn't work unless it does.

Until implies we're just waiting. Unless implies actual evidence, and - in medical procedures - some guarantee of safety.

SF6 plus ultrasound is used to open the blood brain barrier. So if you're pumping a lot of ultrasound into a brain and using a lot of SF6, there are already risks.

but technology is getting better all the time what doesn't work because they only have one Tesla, well shit, let's try it with 100.

It isn't a matter of technology. It's physics and math. These things are already very well understood, just not by investors. And that creates room for the hustle.

Not trying to sound alarmist at all but I am wondering if ultrasounds are safe to be used like this? My understanding is it's basically a high-frequency sound wave which is probably fine for most tissue usage, however here it says it's scattering off of red blood cells. I don't know why that feels so unsettling to me.

Waves scatter off of everything so that's not of concern. Depending on the intensity, frequency, and tissue in question ultrasound can have an effect. Someone elsewhere linked to a couple academic papers on the topic.

I share your hesitation about using this on the brain, at least barring exhaustive long term animal model trials. Subject a mammal to this every day for 10 years and show that there are no negative effects relative to the control.

It feels like ultrasound is solving everything for the last week.

There were a lot of people who declared very loudly last week during the Midjourney discourse that this was an impossible use of ultrasound.

The Midjourney scanners don’t do the same thing that this is using. See how blurry the first image on the page is? That’s what you get from ultrasound through bone like the skull.

They used a trick to inject sparse bubbles into the patient and let them flow through the brain, then looked for the perturbations caused by those sparse bubbles.

The Midjourney scanners aren’t injecting this bubble contrast agent into everyone’s veins.

Absolutely, but it was claims about ultrasound in general

This scanner doesn't inject bubble contrast either. A nurse does it. Obviously a nurse could do that when you use the Midjourney scanner too...

The damage done by Elizabeth Holmes at Theranos goes way further than just that company. There is a lot of distrust now in anything tech that touches on medical devices. Some of it is for good measure, some of it will prevent really cool stuff from happening.

Exactly. The concept itself; a machine that can do a bunch of tests from a whole lot less blood would be amazing but anyone who wants to do this now is automatically "oh so like Theranos" and then not gonna give you money to do this PhD or post doc and do you figure out a way to do this? You can't raise money because everyone's gonna be thinking of Theranos.

Is Aleph an established entity with a track record that should lead us to trust this at face value? I couldn’t find any info on them and the site seems new

Oof did a bit more digging: https://x.com/_marleyx/status/2070260772635312598

> None of us were ultrasound scientists before this. We worked backwards from a desire for brain interfaces and taught ourselves physics, ultrasound, electromagnetism.

Not to say it’s not interesting or neat, but the Silicon Valley approach to solving medical issues doesn’t have a good track record, let’s put it that way

What was impossible is the scale they claim to be targetting.

Half baked images? No one said that is impossible.

I am skeptical of any brain ultrasound claim that doesn’t use skull correction which requires a CT scan.

Very large chunks of vasculature and major arteries are missing in the images they provided. Just because it’s pretty and colorful it doesn’t mean it’s useful.

Perhaps it will one day, but this doesn’t prove much so far. There are several physical challenges to using ultrasound.

I think the more interesting angle is focused ultrasound which is proposed as a solution to a whole lot of diseases

Correlated events :)

The team behind this post is (or at least was as of a few months ago) working with Midjourney.

Who could've thought that injecting SF6 into blood vessels is actually safe enough to be FDA-approved... interesting.

Contrast-enhanced ultrasound (CEUS) with microbubbles has been around clinically for 20+ years. There are many contrast-agent manufacturers, e.g. Bracco (SonoVue/Lumason) or GE Healthcare (Optison). Safety-wise it's probably better than CT iodinated contrast or gadolinium MRI agents, and it's pretty well-established at this point.

Per Wikipedia, it "is a colorless, odorless, non-flammable, and non-toxic gas."

When used as a contrast agent for ultrasound, it "has been used to examine the vascularity of tumours" -- which would be similar to its use in the OP. Then "[i]t remains visible in the blood for 3 to 8 minutes, and is exhaled by the lungs."

So -- not collected and excreted by the liver, as I at first thought.

This is ridiculously cool, but I have a ton of questions.

> The bubbles themselves are pockets of sulfur hexafluoride encapsulated in lipid shells. They're an FDA-approved contrast agent,

Combined with ultrasound, could these be causing damage of any kind to the vasculature?

> A few years ago, a paper came out that blew our minds. The idea was that you can decode what someone is looking at just from their brain activity.

How realistically close can this get to reading thoughts, visuals, etc.?

Do we have a path to imaging people's visual cortex? Their inner lives, dialogues, memories? (Scary thought - this could be used as an interrogation tool without consent. "Did you kill Bob?" could be a simple brain scan.)

Can it be done in real time in a feedback loop and perhaps be used as an advanced reinforcement learning system?

This kind of mind reading could easily become the end of human privacy.

That's bad enough in democracies, but the consequences in more common forms of government seem really dystopian.

Interesting technology, and of course transcranial ultrasound has been around for a while. But ultrasound even at low doses, does stimulate neurons in the brain, and so until we have more data I would be careful about applying it to the entire brain or portions thereof. transcranial focused ultrasound, which has been studied and shows great potential in medical or therapeutic domains, is highly precise, and even then we see that it can have adverse neuropsychological effects depending on the area stimulated, frequency, used, duration, and natural variance between individuals.

I thought the whole "we can guess what you're thinking from an MRI" thing was BS, along the lines: take a small set of photos, image people's brains as they are looking at these pictures, to map to some low-dimensional vector of "brain activity". Then show them some of these (in sample!) pictures, measure the vector of activity and predict back what they were looking at.

Happy to be corrected. But if that's right then this... does the BS thing in a potentially less intrusive way?

How is that BS? If the technique works, you can grow your sample of imaged brains and viewed images ad infinitum, and then why wouldn't I be able to tell what random thing any random person is looking at?

1. Yes, that is generally what those studies did. 2. Th studies are not BS, the popular press description of those studies is BS.

The patterns and locations of activations might be predictive within a sample of images, but cannot discriminate in other samples. The temporal and spatial resolution is too low.

Great. Do you have to hand an accessible non-BS description of one of those?

I have no biology background, but one ML PoV in-depth description I read of these sounded indistinguishable from BS.

How about just getting it more established in orthopedic practices so patients aren't required to 1. See ortho for MRI referral 2. schedule mri at imaging facility 3. PAY $750 - $3000 for an MRI 4. Wait to get back into ortho.

I really don't understand why a fetus' heart can be examined for defects, but you can't use it in the office to tell me if my labrum is torn?

Why in the heck was this comment downvoted? Because that was exactly my thought reading the article: the mind machine interface stuff is weird (and fMRI blood flow is never going to achieve a lot it is a blunt tool which this is related to).

But high resolution imaging of blood flow? That's a pretty great medical diagnostic tool if you can make it more available and cheaper.

Additionally, as an ambulance chaser who looks at medical bills all day, people don't realize how much of the zombie medical debt out there is from scummy ERs (HCA etc) doing 2 or 3 pointless MRIs at $5k a pop.

Ultrasound is very operator dependent. Shoulder ultrasound is very hard. Visualizing the labrum let alone detecting pathology is very very hard and you will miss huge chunks of it due to limited windows.

Ignoring all of this, there are few sub specialist radiologists in the world who could theoretically do this and if you were to pay for their time it would cost more than a highly reproducible and easy to get MRI.

I want to see this done on a primate. Does a monkey recognise a bus? in how much detail? do they dream? Then do cats too. what are they thinking when they sit on the overheating pc? knocking my fresh coffee over?

A whole world of reasoning behind evolutionary solutions to explore.

Can anyone explain how this ultrasound can see through the skull?

I've worked on ultrasound devices and data, the shadows from bone, and distortions caused by tissue types were very difficult. If this device can deal with those distortions it would already be useful for lung imaging.

lungs are much harder than brain and bones (the acoustic impedances of solids and liquids is more similar than solids/liquids vs air: air is very thin)

Amazing spacial precision but the article doesn’t mention the time domain. I assume a brain interface needs to have a pretty high sampling rate in order to meaningfully decode human thought.

Looking at the animations, it’s not hard to imagine this being a fast, low cost test for strokes that can be deployed basically anywhere in the world. Life saving technology.

You can already do this with EEGs for low-ish cost

My phone crawls with all the processing happening on the site.

Interessante, ma siamo ancora lontani. Penso che ti occupi di Risonsanza Magnaetica

We could have standing/lean back MRI. But it would require taller rooms which are non standard.

Where are they injecting these microbubbles? Directly into the brain continuously?

Naive question , isnot there any latency problem considering sound wave .

Is this the same tech the Midjourney scanner device is using?

Yeah, they’re using butterfly network chips for the ultrasound but with some additions.

(IV with microbubbles that they can trace as it flows through the brain & some extra imaging algorithms)

This is complete nonsense. Ultrasound can’t effectively penetrate the skull. The entire thing (and Midjourney’s) is vibed-up nonsense.

The only reason this even exists as a brainfart and hasn’t been immediately laughed out of VC funding is because other imaging modalities require either ionising radiation (illegal to produce without source licences) or an enormous magnet (would be wildly unsafe in the hands of what appear to be circus clowns).

Geoffrey Hinton was hilariously wrong 10 years ago about replacing radiologists, and this is just embarrassing. Maybe try fixing US healthcare funding instead if you want cheaper scans.

Ultrasound can penetrate the skull, esp if through a thin part of the skull (like the temporal bone, which going from the graphic on the website is exactly where they are targeting these waves) and with targeted frequencies.

You are misinformed.

I am a consultant radiologist. Tell that to my 6-month old infants who require MRI with GA because their fontanelles are closed. Transtemporal can give you a poorly resolved image of the 3rd ventricle at a pinch.

“Targeted frequencies” - righto.

it's widely accepted that ultrasound applied to the skull is even audible, this was discovered shortly after WWII: Gavreau in 1948 and then Pumphrey in 1950, who proposed the middle ear ossicles simply form a low-pass filter, although the situation is a lot more cloudy to this day: the topotonic relationship or the subjective frequencies don't seem to correspond to their actual frequencies. It's unclear if that is due to intermodulation distortion (non-linear frequency mixing) or perhaps even simply the frequency relationships being novel to the untrained ear (for the first time exposed to ultrasound, well not really, when biting on food or generally clenching the teeth and associated friction between upper and lower teeth are bound to emit countless ultrasounds, but not exactly harmonic oscillators, so perhaps the brain has only learn't time domain associations and little to no frequency domain associations for these higher frequencies)

If you believe ultrasound categorically can not penetrate the skull, while the much longer used Weber and Rinne tests clearly demonstrate bone conduction of sounds by placing a tuning fork against the skull, so I wonder how you explain that: audible frequencies can pass but independently defined ultrasound is unable to pass?

> If you believe ultrasound categorically can not penetrate the skull

No, of course bone can conduct sound, like any other solid. What I said was ultrasound cannot *effectively* penetrate, ie get a diagnostic image back out in an adult. This is what is being purported here, and is the nonsensical part.

It definitely can penetrate the skull, and transcranial focused ultrasound has been around for a few years now with plenty of studies.

So that development isn't new; what's new is to use it broadly for imaging instead of for highly targeted stimulation.

Not to the level of clarity and detail presented here, which is not possible from a basic acoustics physics premise. The “technical blog” is marketing fluff.

that's why I said: "what's new is to use it broadly for imaging"

That’s the made up part though.

right, that may indeed be so

There is a line of research right now using ultrasound as a king of treatment for mental disorders, similar to TMS approaches. It's not that the sound can't get there, it's whether you can get information back from it.

Imagine a future where we could distill some kind of “weights” from living human brains when we’ve run out of quality training data for AI using this tech.

Sulfur hexafluoride escaping is exceptionally damaging as a greenhouse gas, is there nothing else they can use?

Edit: wow, serves me right for asking / not understanding that contrast means SF6...

Their goal is contrast-free imaging — read the bottom of the article.

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