Identification and Quantification of Myofascial Taut Bands With Magnetic Resonance Elastography

Experimental setup of MRE on subjects. (I) Pressure chamber connected to a remote loudspeaker. (II) Acrylic bar vibrator. (III) Positioning jig. (IV) Radiologic marker.

Wave propagation patterns. (A) MRE phase image of a homogeneous bovine gel phantom. The vibratory source located at the left border produces a planar waveform. (B) MRE phase image of the bovine gel taut band phantom. Note the chevron-like pattern of the waves as they travel away from the source located at the left border. (C, D) Finite element simulation of the homogeneous and taut band phantom models. Note the reoccurrence of the chevron-shaped waveform in the taut band simulation. (E) MRE phase image of upper trapezius of the control subject superimposed to an MR image of the same region. Note the uniform, planar nature of the waves produced by the vibratory source located on the spine of the scapula—(I) spine of scapula; (II) planar wave fronts in upper trapezius; and (III) cervical spine. (F) MRE phase image of upper trapezius of the patient with myofascial pain superimposed to an MR image of the same region. The line appearing in the figure’s center indicates the physician’s localization of the taut band. Although more difficult to distinguish than in the phantoms, the V-shaped wave fronts are again apparent. λ_t indicates the wavelength in the chevron-shaped wave fronts region, and λ_s indicates the wavelength in the surrounding muscle—(I) spine of scapula; (II) chevron-shaped wave fronts observed in the region of taut band palpated by the physician; and (III) cervical spine.