Explore a conceptual handheld wrist scanner in 3D. Tune its fields, excite proton spins, encode space with magnetic gradients, receive a simulated spin echo, and reconstruct a synthetic MRI slice from genuine sampled Fourier data.
A magnet must create a stable static field. Gradient coils add position-dependent field changes. A radiofrequency coil excites and detects nuclear magnetization. These are separate jobs.
The following controls feed a simplified spin-echo signal model and 2D Cartesian k-space acquisition—not merely a visual filter.
MRI is not a camera. Shrinking the coils also shrinks the sensitive volume, while fields, interference, heat, vibration, RF exposure and reconstruction remain demanding.
Permanent magnet geometry, magnet gap, field mapping, shielding and high homogeneity across the target volume.
Passive/active compensation for magnet imperfections, temperature changes and sample-dependent field shifts.
Current drivers, calibrated coil fields, spatial encoding and limits on heating, acoustic noise and nerve stimulation.
Tuned coil, transmit pulses, decoupling, low-noise amplifier, receiver protection and impedance matching.
RF reference oscillator, coherent quadrature detection, signal filtering and synchronized analog-to-digital conversion.
Fourier transform plus optional sensitivity correction, field correction, motion mitigation and robust image quality checks.
Receiver bandwidth, cable isolation, local shielding, interference cancellation and sensor coupling.
Ferromagnetic screening, implanted devices, RF heating/SAR, gradient exposure, electrical safety and clinical validation.
Your chosen image resolution, field stability and RF sensitivity determine the main trade-offs.
The image is generated from a synthetic proton-density / T₁ / T₂ wrist phantom, forward Fourier-transformed into complex k-space, sampled row by row with noise and artifacts, then inverse Fourier-transformed. No patient data and no real RF acquisition.
Tissue signal formula assumes an ideal 90°/180° spin-echo sequence; RF slice profiles, real coil field maps, true noise covariance, relaxation heterogeneity and system calibration are deliberately simplified.
A small excess of hydrogen nuclear moments aligns with the static field, creating net magnetization.
RF at the Larmor frequency tips magnetization away from B₀; spins precess coherently.
Applied magnetic gradients make precession frequency and phase depend on spatial position.
Transverse magnetization induces a tiny voltage in a tuned receiver coil; a 180° pulse creates a spin echo.
Phase-encoded k-space samples are inverted by a Fourier transform into spatial contrast.
MRI relies on nuclear magnetic resonance (NMR), not ionizing radiation. A static field and RF pulse alone measure an aggregate resonance signal. Imaging requires spatial encoding and reconstruction. Low-field and portable MRI exist, but the magnet, stable field over the desired field of view, noise isolation and receive coils can still require systems weighing hundreds of kilograms. This illustrated clamp is a design thought experiment for a very small target, not a proven MRI product.
Explore a conceptual handheld MRI in 3D. Adjust spin-echo and spatial-encoding controls, then reconstruct a synthetic image from sampled Fourier data.
This interactive physics lab demonstrates a conceptual handheld wrist scanner, proton spin behavior, a simplified spin-echo sequence, spatial encoding, and reconstruction of a synthetic MRI slice from sampled Fourier data.
Use it to explore how magnetic-field and pulse-sequence parameters affect a simplified signal and image reconstruction, or to inspect the conceptual scanner assembly and sequence stages.
Students, educators, and technical readers learning introductory magnetic-resonance and imaging-physics concepts. It is a teaching simulator, not a diagnostic tool or medical device.
Controls include field strength, sequence timing, gradient and RF settings, matrix size, field of view, averages, inhomogeneity, motion, and coil gap. Outputs include a simulated spin-echo signal, sampled spatial-frequency data, and a synthetic 64 × 64 image.
The lab does not demonstrate a diagnostic-quality handheld MRI. It establishes no hardware compliance, safety certification, validated magnet layout, or clinically reliable imaging, and it is not a construction specification. It does not replace medical advice or an actual MRI system.
The physics calculations and reconstruction run in the page without a remote MRI service. The page also uses the site's standard Google Analytics page-view tag when online. Settings are not saved across reloads.
No. It generates a synthetic teaching image and is not a medical device or diagnostic-quality scanner.
No. This physics lab is a separate page with its own spin-echo, spatial-encoding, and Fourier-reconstruction controls.
SolvProb builds custom web apps, simulations, automation tools, and interactive experiences.
Talk to SolvProb →