The main objective was to make the physical principles underlying magnetic resonance imaging more easily accessible to A-level and beginning undergraduate students or even the general public.

We illustrate the concept of magnetic resonance using sound waves and tuning forks. First, a single tuning fork is excited using a speaker connected to a tone generator. When the tone generated by the speaker is resonant with the frequency of the tuning fork, the latter is excited, producing an audible signal after the speaker is turned off. Although a classical phenomenon, the excitation of the tuning fork with the speaker illustrates the excitation of a proton in a magnetic field using a resonant RF pulse.

The signal from the tuning fork decays exponentially, which is both audible and can be visualized on a screen to explain T2 relaxation.

Using an array of tuning forks with different resonant frequencies, slice selective excitation using magnetic field gradients can be demonstrated by tuning the speaker to different frequencies. Multiple tuning forks can be excited at once and the combined sound emitted by the array of tuning forks can be recorded. The peaks in the spectra then show which tuning forks emitted the sound waves.

To illustrate T2 contrast the experiment can be made more sophisticated by using multiple tuning forks with the same resonance frequency but different relaxation rates, which can be achieved, e.g., by afixing small lumps of blue tack or similar to the tuning forks to introduce additional damping.

The experiments were set up and performed by A-level students as a summer project under academic supervision. Although the students, who had no prior background in MR physics, found it initially challenging, the results in terms of the level of understanding of basic concepts at the end of the placement were encouraging and suggest that this approach may be useful for MR education.