Sonography of the pleura

The CME review presented here is intended to explain the significance of pleural sonography to the interested reader and to provide information on its application. At the beginning of sonography in the 80 s of the 20th centuries, with the possible resolution of the devices at that time, the pleura could only be perceived as a white line. Due to the high impedance differences, the pleura can be delineated particularly well. With the increasing high-resolution devices of more than 10 MHz, even a normal pleura with a thickness of 0.2 mm can be assessed. This article explains the special features of the examination technique with knowledge of the pre-test probability and describes the indications for pleural sonography. Pleural sonography has a high value in emergency and intensive care medicine, preclinical, outpatient and inpatient, in the general practitioner as well as in the specialist practice of pneumologists. The special features in childhood (pediatrics) as well as in geriatrics are presented. The recognition of a pneumothorax even in difficult situations as well as the assessment of pleural effusion are explained. With the high-resolution technology, both the pleura itself and small subpleural consolidations can be assessed and used diagnostically. Both the direct and indirect sonographic signs and accompanying symptoms are described, and the concrete clinical significance of sonography is presented. The significance and criteria of conventional brightness-encoded B-scan, colour Doppler sonography (CDS) with or without spectral analysis of the Doppler signal (SDS) and contrast medium ultrasound (CEUS) are outlined. Elastography and ultrasound-guided interventions are also mentioned. A related further paper deals with the diseases of the lung parenchyma and another paper with the diseases of the thoracic wall, diaphragm and mediastinum.