Source: saved session 01a155d2-aca9-759a-982e-f3e88cd96468, October 19, 2026.
The original detailed write-up is preserved verbatim below. Desktop paths and verification claims refer to that original session, not this import. Educational material only; not a clinical protocol or medical device. Clinical statements, diagnostic thresholds, and treatment recommendations have not been independently verified during import. Original model assumptions and limitations are preserved; independent clinical review is required before teaching or patient-care use.
I built the figure. Open ~/Desktop/02_projects/anatomy-stroke-ct/stroke-ct-light.html (there's also a dark version, stroke-ct.html).
What it shows: an ER CT scanner with the front cover off. A patient lies on the table with the head in the gantry. The X-ray tube and the detector arc spin around the head, and during each scan the X-ray beam lights up as it cuts one slice through the head. A contrast injector stands beside the table with its line running to an IV in the right arm. A monitor on a cart shows the slice and the call, and a dial on the cart counts hours since the patient was last known well.
What you can do with it:
- Switch between a clot in the left MCA and a bleed in the right putamen.
- Run the three scans in order:
- Plain CT (no contrast): asks blood or no blood. A bleed is bright from the first minute. A clot stroke looks normal early and only darkens as the dead tissue takes up water; you can watch it appear by about 6 h.
- CT angiogram: contrast stops at the left M1 and nothing fills beyond it, which means a large blocked artery. In a bleed it shows the spot sign.
- Perfusion CT: shows the dead core next to the brain that can still be saved, then applies the late thrombectomy rule (core under 70 mL, ratio at least 1.8, savable tissue at least 15 mL).
- Switch the brain window (width 80, center 40) to the narrower stroke window (width 40, center 35). Early damage becomes visible about 2 hours sooner.
- Drag the time slider from 0 to 24 h. The image, the HU numbers, the ASPECTS score and the treatment call all update. The call covers the 4.5 h clot-buster window, thrombectomy, and the bleed steps (no clot-buster, blood pressure toward 140, neurosurgery).
Below the figure is a large copy of the slice with the numbers behind it, plus notes on why CT comes first, door-to-scan and door-to-needle targets, doses and time windows. With no input it runs a tour on its own.
The time course is a simplified teaching model with approximate rates, not clinical guidance. The page says so.
Checks: the kit's geometry audit and line check both pass in light and dark, also while the beam is on. It runs at about 59 fps in headless Chrome, and the phone width, reduced-motion mode and every scan step render without errors.
Files are in ~/Desktop/02_projects/anatomy-stroke-ct/. To rebuild:
node build.mjs && node build.mjs --light