Detection of mechanical vibrations by magnetic resonance: elastomagnetic resonance spectroscopy (EMRS)

The previously tested MRI methods quantitative measurement of mechanical properties required a synchronization between MRI acquisition pulses and mechanical stimulation. Two new unsynchronized methods: (1) with Bo static field gradient Go and (2) with a B1 radio-frequency field gradient G1 are proposed. The methods are usable without any a- priori knowledge of the intensity, direction and frequency of the mechanical waves. A specifically modified SPAMM sequence has been used, operating on a 0.2 T MRI system. The proposed methods are sufficient fast (acquisition time less than 5 seconds) for a routine clinical use.