A camera that captures not your face but your brain itself — from the inside, layer by layer. Conventional tomographs often produce blurry images: fine details merge like letters on a fogged-up window. Engineers set out to build a device that sees clearly even what is smaller than a millimeter.
To do this, they took crystals that catch flashes from a radioactive tracer in the blood and made them thicker—20 millimeters instead of 15. A thicker crystal stops more signals, like deep snow muffles footsteps. And to avoid losing precision, they added hint layers: each layer reports the depth at which the signal originated. It's as if the snow remembers where the foot stepped.
Tests on a phantom, a plastic brain replica with hot spots, showed that the device can distinguish points the size of a grain of sand. That means a doctor could spot a disease focus at its earliest stage. Or see a thought race across the cortex while a person solves a puzzle.
A thin crystal catches fewer signals but yields a sharper image. A thick one does the opposite. The engineers found a balance: 20 millimeters with three hint layers. This way, the tomograph of the future can image the brain quickly and without smeared edges, like a skilled photographer who never misses a detail.
The tomograph in question detects a signal from a substance injected into the blood that glows from within. The thicker the receiving crystal, the more light it collects, but the harder it is to tell exactly where the signal came from. So they added layers that act like address labels.
In the series 'Altered Carbon,' consciousness is scanned with incredible detail. This tomograph is a step toward seeing the brain almost that clearly, though without personality transfer — for now.