A review of the ultrasound assessment of diaphragmatic function in clinical practice

Ultrasonography is the only non-invasive, non-ionizing imaging technique widely available to directly assess diaphragmatic function. Two different sonographic approaches permit the assessment of muscle thickening in the zone of apposition and excursion of the dome of the diaphragm. Thanks to the new hand-held ultrasound instruments, the morphology and function of the diaphragm can be assessed in different settings, such as outpatient clinic, pulmonary function test laboratory, hospital department and intensive care unit, and under different conditions. Despite the existence of different acoustic views and several codified approaches, a comprehensive sonographic examination has never been standardized for clinical use. In this review, we summarize the clinical indications, methods and perspectives of the technique in adults.