HandheldMRI

Explore a conceptual MRI spin simulation with adjustable TR, TE, noise, tissue readouts, signal plots, and k-space visualization.

What this tool does

HandheldMRI is an educational 3D visualization of simplified MRI behavior. It displays tissue voxels and spin directions, applies simulated 90° and 180° RF pulses, models T1/T2 relaxation, and shows localized echo signal activity in signal and k-space panels.

Who this is for

• Students learning the relationship between RF pulses and relaxation
• Developers or educators demonstrating MRI concepts in a browser
• Curious users exploring a visual, non-diagnostic simulation

How to use this tool

1. Tap or click the opening overlay to initialize the simulation
2. Drag to rotate the 3D view, pinch to zoom, and use a two-finger drag to pan on touch devices
3. Center the crosshair on a voxel to inspect its tissue type, T1, T2, and proton-density values
4. Adjust TR, TE, and noise; the app keeps TE below TR
5. Press Start Scan to observe pulse phases, signal rays, the signal plot, and k-space activity

Inputs

Inputs are 3D camera gestures, TR from 200–2000 ms, TE from 10–200 ms, and noise from 0–0.5. The simulated creature and tissue parameters are built into the page; no scan data or medical images are imported.

Outputs

The app renders a voxel-and-spin 3D scene, target tissue readouts, scan status and cycle counters, FPS, localized signal rays, a scrolling signal plot, and a k-space intensity display. This is a conceptual visualization, not a diagnostic MRI tool or a reconstruction of clinical data.

Example use cases

• Compare how different TR and TE values affect simulated signal behavior
• Demonstrate the purpose of 90° excitation and 180° refocusing pulses
• Use the tissue readout and k-space panel as prompts for an MRI lesson

Frequently asked questions