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PET Scanner: Coincidence Detection

Interactive PET scanner simulator: radioactive tracer decays emit back-to-back annihilation photons, a detector ring registers coincidences, and lines of response backproject into a reconstructed image — tune activity, coincidence timing window and positron range to see how each degrades or sharpens the picture.

Medical Technology & Imaging Physics3DModerate60 FPS

Positron emission tomography locates a radioactive tracer inside the body without ever directly "seeing" it. Each decay emits a positron that annihilates with a nearby electron, producing two gamma photons that fly apart in opposite directions; a ring of detectors around the patient catches both within a tight timing window and records the straight line between them. No individual line pinpoints the source, but as thousands of these lines of response accumulate, backprojection makes them pile up densest exactly where the tracer is. This simulator lets you tune the tracer activity, the coincidence timing window and the positron range blur to see, in real time, how each one trades image sharpness against noise from spurious random coincidences.

⚙ Under the hood

PET scannuclear medicinepositron annihilationcoincidence detectionmedical imagingbiophysicstomography

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install