  Lung ultrasound surface wave elastography (LUSWE) is a novel noninvasive
technique for measuring superficial lung tissue stiffness.The purpose of this
study was to translate LUSWE for assessing patients with interstitial lung
disease (ILD) and various connective diseases including systemic sclerosis
(SSc).In this study, LUSWE was used to measure the surface wave speed of lung
at 100 Hz, 150 Hz and 200 Hz through six intercostal lung spaces for 91
patients with ILD and 30 healthy control subjects. In addition, skin
viscoelasticity was measured at both forearms and upper arms for patients and
controls. The surface wave speeds of patients' lungs were significantly higher
than those of control subjects for the six intercostal spaces and the three
excitation frequencies. Patient skin elasticity and viscosity were
significantly higher than those of control subjects for the four locations on
the arm. In dividing ILD patients into two groups, ILD patients with SSc and
ILD patients without SSc, significant differences between each patient group
with the control group were found for both the lung and skin.No significant
differences were found between the two patients group, although there were some
differences at a few locations and at 100 Hz. LUSWE may be useful for assessing
ILD and SSc and screening early stage patients.
