Transthoracic Shear Wave Elastography (SWE) in lung subpleural lesions: a preliminary report

Background: The new generation shear wave elastography (SWE) captures and calculates in real time the propagation speeds of transverse pressure waves and analyze tissue elasticity. Aim: Our aim was to assess if SWE may represent a new quantitative method suitable also in the study of lung subpleural lesion. Methods: 190 consecutive patients with lesions adherent to pleural surface on chest CT were subjected to US examination and SWE analysis. SWE was performed also in 25 healthy volunteers (without active pleuro-pulmonary pathologies). Patients with suspected malignant lesions were subjected to transthoracic biopsy procedure. Results: We found no statistical difference in stiffness between primary lung cancer, lung metastasis and pneumonitis (p=NS) nor between different histological types of primary lung cancer (p=NS). However, excluding lesions with necrosis at CT, pneumonia showed a statistically significant increased stiffness (probably due to the presence of fibrotic tissue in slowly resolving pneumonia) with respect to lung cancers. We found a statistically reduction in stiffness in lesions associated with pleural effusion compared to that without pleural effusion, both between primary lung carcinomas (p Conclusion: Transthoracic SWE may be influenced by several condition such as pleural effusion, fibrosis, calcification, necrosis, chest wall fat and pulmonar air. In our experience it wasn’t able to distinguish between benign and malignant lung lesions nor between different histological types of lung cancer. Further studies, on a larger scale, would be desirable to try to overcome these limits.