Thoracic Ultrasound: Technique, Applications, and Interpretation

Thoracic ultrasound is used at the bedside in emergency and critical care settings. Advantages of ultrasound include rapid real-time, low-cost, diagnostic information that can direct patient care without the use of ionizing radiation. We describe methods on how to perform lung ultrasound, with the intent to educate the radiologist who might otherwise be relatively unfamiliar with thoracic sonography. We describe and depict the normal sonographic appearance of lung anatomy. We also show the sonographic appearance of a wide range of lung and pleural pathologies such as pneumonia, pneumothorax, as well as lung and pleural masses. We review various lines and signs described in the literature, such as A-lines, B-lines, the stratosphere sign, and the bat-wing sign. Finally, we correlate our findings with chest x-ray and computerized tomography to emphasize the anatomy.