Limits and disclaimer

What this model is good for, and what it is not.

One patient

The arteries come from a single real MRA case. They are not an average and not a typical anatomy. This patient has a complete circle of Willis, and many people do not. The ACom and PCom switches show how flow can cross, but they do not model the variants you meet in practice.

What is schematic or generated

• Small cortical branches are generated by an algorithm and tuned to real angiograms. They are not patient data. Distal branches in the scan itself are incomplete.
• Brain and skull come from a template and atlases and are placed on the vessels by landmarks, with an error of a few millimetres. The bone is schematic.
• Optic nerves, tracts, eyes, pituitary and parts of the venous system (transverse and sigmoid sinuses, jugular veins) are schematic.
• The C-arm window in the controls is a drawing, not a scaled device.
• Atlas parcellations (Brodmann areas, nuclei, lobules, sulci) are approximate and are not drawn on this patient's own brain.

Stylized timing and physics

• The projection is orthographic, so there is no cone-beam magnification.
• Contrast flow is a simple model on a graph. There is no capillary blush.
• Venous timing is stylized: capillary delay, flow speed and sinus filling are invented to look right, not measured. There is no deep venous system beyond the vein of Galen.

Stroke simulation

• Territory borders come from an atlas average (Johns Hopkins Arterial Atlas), and the branch inside each territory comes from one patient's vessel graph. Real territories vary between people.
• Core growth, penumbra, edema and midline shift are smooth curves with invented time constants. They are not a prediction for any patient.
• Collaterals are limited to ACom and PCom. There is no leptomeningeal flow, no reperfusion and no hemorrhage.
• Cerebellar and brain stem areas are rough. The findings list is a short textbook summary.

Visual pathway

The fibres are least-cost streamlines through a probability map, not tractography of this patient. The map reaches only part of the real anterior extent of Meyer's loop. The field charts show classic teaching patterns; real defects vary.

Found a mistake?

Anatomy or teaching content that looks wrong is worth reporting. Please use the feedback page.

Please do not

• use it to decide how to treat a patient or to plan a procedure;
• use it commercially without permission of the data owners (see Sources and licenses).