In this Monday afternoon presentation, Sergio Sanabria, PhD, of the University of Zurich will share results from a study that found that using this new B-flow sequence and measuring bite force stiffness with SWE was effective for tracking myofascial pain syndrome treatment.
Myofascial pain is related to tissue stiffening and is often treated with Botox. But gauging treatment response can be challenging, Sanabria's group noted. The team set out to evaluate the use of ultrasound to assess treatment effectiveness.
The researchers used a B-flow ultrasound sequence based on 2D digital image correlation that allowed images to be acquired without contrast. Fifty units of Botox were injected in both the left and right masseter muscles of a female patient with myofascial pain syndrome; the team then used SWE to measure the velocity values of the left muscle, asking the patient to alternate between relaxed and biting states.
Ultrasound showed that the Botox moved along the muscle fiber three times as quickly on the axial plane compared with the lateral plane. Shear-wave velocity ranged between 1.52 m/sec and 3.98 m/sec for bite force between 0 N and 450 N.
These results led the team to conclude that it's better to inject patients multiple times with smaller amounts of Botox in the masseter muscle instead of a single, larger injection.
"The presented B-flow method is promising for a wide range of applications, where contrast-enhanced US is not feasible," the group concluded. "SWE could have diagnostic properties for differentiating idiopathic masticatory myalgia from other diseases affecting the masticatory muscles."
