Thoracic ultrasound elastography in pleural and subpleural diseases: a narrative review

Ultrasound elastography measures tissue stiffness and has demonstrated clinical utility across multiple medical specialties. In respiratory medicine, its application is increasingly explored for pleural and subpleural lesions, pleural effusions, and pneumothorax. This narrative review examines current evidence for thoracic ultrasound elastography, highlighting potential benefits and key limitations. Several studies suggest that elastography can differentiate malignant from benign pleural lesions and show superior sensitivity for elastography-guided versus traditional ultrasound-guided pleural biopsy. However, significant challenges hinder clinical implementation: lack of standardised protocols, variability across ultrasound systems, operator dependency, and limited multicentre validation. The "elasto-lung point" sign has been described as potentially useful for pneumothorax detection, but its incremental value beyond conventional ultrasound remains uncertain and requires further investigation. Elastography has also been preliminarily studied for non-expandable lung detection, although current evidence suggests that M-mode ultrasound may perform better. Integration with artificial intelligence holds promise to enhance future diagnostic capabilities. Overall, thoracic elastography represents an innovative approach that requires substantial validation before routine clinical use can be recommended. Future priorities include protocol standardisation, rigorous multicentre studies, and demonstration of impact on patient outcomes.