A new perspective for lung ultrasonography, preliminary results

Lung ultrasonography (LUS) is increasingly applied for the diagnosis of lung diseases. However, diagnoses are often based on imaging artifacts, e.g., B-lines, ultimately being qualitative and subjective. Aiming at gaining insight on the genesis of B-line artifacts, and on their link to the anatomical structures related to pathological conditions, dedicated lung-mimicking phantoms were manufactured and imaged with the ULA-OP research platform, proving access to raw radio-frequency (RF) data. To mimic a healthy and a diseased lung, two phantom types were made, being gelatin phantoms containing bubbly-layers composed of mono-disperse microbubble populations of different diameters: 140 and 80 μm, respectively. In fact, in various pathological conditions the size of the alveoli (air sacs composing the lung parenchyma), and hence the lung volume occupied by air, is alterated due to, e.g., fluid extravasation, alveolar collapse, and inflammation. Results show the appearance of B-lines only for phantoms designed to mimic pathological condition, confirming the link between artifact formation and reduction of air spaces dimensions. These preliminary results may be applicable to LUS, opening the way to the development of a quantitative ultrasound method dedicated to the lung.