Ultrasound of lung parenchyma—current state and future

The evidence base supporting the use of thoracic ultrasound to assess the lung parenchyma has expanded and consolidated itself significantly within the last decade. Thoracic ultrasound for lung parenchyma assessment is now finding its way into statements and clinical practice guidelines for several conditions in various settings. Since assessment of patients with possible chest disease is a very common clinical scenario, knowledge of the various types of chest imaging is essential for any physician. The most common indication for thoracic ultrasound for lung parenchymal assessment is for screening and diagnostic purposes. Several new studies have, however, demonstrated a possible large potential for using thoracic lung ultrasound to monitor lung diseases. The recent COVID-19 pandemic has increased the scope of lung parenchymal ultrasound, from diagnosis to monitoring of the disease. Deep learning of contrast-enhanced thoracic ultrasound to aid diagnosis is a new developing area. Despite increasing use of thoracic ultrasound in respiratory medicine, a consensus on assessment of competencies, and education is lacking. The aim of this review is to provide the reader with a focus overview of the current use and diagnostic limitation of thoracic ultrasound for assessment of the lung parenchyma, and future development.