Background Elastography Ultrasound (EUS) is an ultrasound-based method, which allows the qualitative or quantitative measurements of the biomechanical properties of tissues. EUS can be performed using compression-wave or more recently, shear-wave propagation, using acoustic radiation force impulse (ARFI) imaging and associated new virtual touch imaging (VTI) and virtual touch quantification (VTQ) technologies. ARFI estimates tissue stiffness in real time and is quantitative and user independent. The use of VTQ technology has never before been reported in patients with systemic sclerosis (SSc).
Objectives To compare the relative and absolute soft tissue stiffness in patients with SSc and healthy controls using compression EUS and ARFI.
Methods Twenty-six patients with SSc and twenty-five age and gender matched healthy controls were included in the study. Relative and absolute stiffness of soft tissue were measured on the palmar aspect of the third metacarpophalangeal joint, plantar aspect of the third metatarsophalangeal joint and over the heel. All these sites have an anatomical features associated withbiomechanical stress.
Results There was a trend towards greater tissues stiffness values in SSc patients and controls using all three technologies. VTQ was the most consistent measure and provided absolute outputs (Table 1).
Conclusions Measurements of tissue stiffness by EUS add a new dimension to the assessment of soft tissues in SSc. The compression EUS and VTI technologies have some limitations for the real-world application in SSc. VTQ however, is a promising technique that provides absolute and objective quantification of tissue stiffness. In the longer term VTQ and similar technologies may offer an objective and quantitative alternative tools to clinical measures such as the modified Rodnan Skin Score.
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Disclosure of Interest None Declared