Thoracic ultrasound transducer

A 3.5 MHz phased array ultrasonography probe is shown over the right lateral chest wall, just below the angle of the clavicle. The arrows indicate the directions the transducer may be moved during a systematic examination. Transducer movement should be in only one direction at a time until the entire area of interest has been imaged. The purpose of the examination is to outline the craniocaudal and lateral extents of the pleural effusion, determine whether the effusion is free-flowing or septated, and identify adjacent structures.