Ultrasound lung spectroscopy: Preliminary in-vivo results

Abstract

Nowadays, lung pathologies are mainly diagnosed by X-ray imaging, with the golden-standard being computed tomography (CT). However, CT is not available at patients’ bed, not always accessible, and expensive. Additionally, CT delivers a relatively high radiation-dose, with the risk of an increased possibility to develop cancer. Recently, attention is shifting toward ultrasound imaging, which would offer a more portable, more accessible, cheaper, and safer alternative. However, despite promising clinical findings, technical development is lacking. In fact, ultrasound imaging is not optimal for lung investigation being designed for low acoustical impedance mismatches. As a consequence, clinicians base their decisions on qualitative interpretations and imaging artifacts, such as the well-known B-line artifact. In this work, following a recently published in-vitro study (L. Demi et al., “Determination of a potential quantitative measure of the state of the lung using lung ultrasound spectroscopy,” Scientific Reports, 2017), we report on the first preliminary in-vivo results. Standard B-mode, multi-frequency imaging-sequences, and RF-data, were acquired. Consistently with the in-vitro study, clinical data show that B-lines can be characterized on their frequency content. These results further support the hypothesis that the analysis of ultrasound spectral features can be used to develop a quantitative method dedicated to the lung.