Lung ultrasound surface wave elastography

A lung ultrasound surface wave elastography (LUSWE) technique is developed to measure superficial lung tissue elastic properties. A small, local, and short 0.1 second harmonic vibration is generated by the indenter of a handheld shaker on the skin of a subject. The ultrasound probe is positioned about 5 mm away from the indenter in the same intercostal space to measure the generated surface wave propagation on the lung. In this paper, the protocol of LUSWE is standarzied for assessing patients with interstitial lung disease. We demonstrate the surface wave speed at 100 Hz for a healthy volunteer using this protocol. The wave speed in the upper right lung was 1.90 ± 0.02 m/s (mean ± SD). The wave speed in the lower right lung in the mid-axillary line was 1.93 ± 0.08 m/s and 2.06 ± 0.13 m/s in the mid-scapular line. The corresponding values in the left lung were, respectively, 2.12 ± 0.19 m/s, 2.08 ± 0.15 m/s, and 2.15 ± 0.12 m/s. These values are consistent with our previous measurements. LUSWE is a safe and noninvasive technique for assessing patients with interstitial lung disease.