Imaging a living brain through the skull with ultrasound and a cloud of microbubbles
Aleph claims the most detailed vascular image of a human brain ever taken with ultrasound through an intact skull, plus reconstructions of what a subject was looking at. Two brain-imaging specialists in the thread say the skull doesn't let ultrasound do that.
The technique injects sparse, FDA-approved sulfur-hexafluoride microbubbles and uses their isolated blur to localize each one far below the diffraction limit — building a vascular map 100x finer by volume than CT, then decoding neural activity from blood flow.
The expert pushback is blunt: a neuroscientist cites papers that even low-dose ultrasound disrupts myelination, and an ultrasound-device engineer asks the question the post never answers — how does it see through bone at all?
What Aleph says it built
Aleph's writeup claims transcranial ultrasound imaging through an intact skull at a level of detail it calls “the most detailed vascular image of a living human brain … captured with ultrasound through the skull” — roughly “100 times greater volumetrically than comparable CT.” The trick is super-resolution via sparsity: inject FDA-approved sulfur-hexafluoride microbubbles sparsely enough that each one's blur doesn't overlap its neighbor's, then fit the center of each “far below the diffraction limit.” Accumulate millions of bubble positions in flowing blood and you reconstruct fine vasculature; because firing neurons pull in more blood, the same signal indirectly maps activity. The post even shows decoded reconstructions of images a subject viewed — a double-decker bus, a wading bird, a market scene.
The specialists who say the physics doesn't allow it
The fiercest rebuttal came from someone who works on the relevant tissue. A neuroscientist who does large-scale electron microscopy of brain wiring didn't argue resolution — he argued safety, with citations:
“Even low-dose ultrasound (what they use on pregnant women) results in ultrastructural changes in brains … specifically at the nodes of Ranvier (the gaps between myelin along axons).”
An engineer who has built ultrasound devices raised the question the post glides past: “Can anyone explain how this ultrasound can see through the skull? … the shadows from bone, and distortions caused by tissue types were very difficult.” The harshest verdict simply called it “vibed-up nonsense,” on the grounds that ultrasound can't effectively penetrate the skull at all.
The pattern-recognition critique
Even readers who found it “ridiculously cool” hedged. One commenter walked through why the super-resolution trick leans entirely on bubble sparseness — and red blood cells, packed roughly 20µm apart, are anything but sparse, which undercuts the post's aspiration to drop the contrast agent later. And a reader who's watched this movie before named the genre: “Every few years one of these ultrasound companies comes around … The tell is 'super resolution', 'brain computer interface' and 'mixed modality.'” The vascular images may well be real and useful. The leap from “we can map blood flow” to “we can read your inner life” is the part the thread refused to grant.
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