Diagnostic ultrasound

Diagnostic ultrasound has developed into an imaging modality due to its noninvasive capabilities. Diagnostic ultrasound is used in examining a wide variety of tissues. The parts of the body that can be imaged with ultrasound are limited because of the means by which it penetrates tissue. Imaging is accomplished by recording echoes of ultrasonic wave pulses directed into the tissues. Ultrasound does not readily cross a tissue–gas or tissue–bone boundary so deeper structures are obscured. Thus, transdermal spinal ultrasound of the adult spine and its contents has limited medical application as a screening, diagnostic or adjunctive imaging tool. Ultrasound may be effectively used in the soft-tissue components around gas-containing and bony structures but not within or deeper to those structures. Spinal ultrasound may also be used for intraoperative imaging or guidance as well as prenatally and in the newborn or infant because of the minimal ossification of the bone and the short depth between the skin and the spinal subarachnoid space.