Measuring Thickness of the Normal Diaphragm in Children Via Ultrasound.

Ultrasound measurement of the diaphragm will be performed with the use of a Sono Site SII, portable system in B mode with the child in a 30-degree supine position. The diaphragm thickness will be measured with a high frequency (4-10 MHz) linear array transducer placed in the ninth or tenth intercostal space between the anterior and midaxillary lines in the zone of apposition between lung and liver.