Physics, Techniques and ProceduresResonance
synchronous vibration; a physical process entailing the exchange of energy between systems having the same natural frequency. Resonance is a very widespread phenomenon encountered in e.g. musical instruments, radio transmitting and receiving, vibrating engine parts and bridges, etc, etc. In radiology, the phenomenon is important in e.g. magnetic resonance imaging and
ultrasound applications.
Nuclear magnetic resonance involves exchange of energy between photons (transmitted radiofrequency electromagnetic radiation) and magnetic nuclei (e.g. protons) having the same frequency (radiation frequency and
precessional frequency, respectively). In
ultrasound imaging, the energy of the echo can be transferred to the
piezoelectric crystal because the frequency of the echo is very close to the natural frequency of the crystal.
HJS