Ultrasound structure of the human nail plate.

The structure of the normal human nail plate is described using an ultrasound scanner (20 MHz A). Postmortem studies, including examination of nail plate biopsy specimens before and after desiccation, were performed and compared with in vivo structures. Two compartments could be identified in the nail, ie, a dry and superficial compartment with the ultrasound velocity of 3103 m/s and a humid and deeper compartment with an ultrasound velocity of 2125 m/s. The ultrasound velocity of the entire nail was 2459 m/s, and the water content was 35% wt/wt. Underneath the nail, echoes from the nail bed were seen. Ultrasound was concluded useful for noninvasive measurement of nail thickness and examination of internal nail structure.