Sometime in the past few million years, collapse at the top of the cave and surface erosion created the natural entrance of Carlsbad Cavern. This opened previously hidden underground cave passageways to the world above for the first time.
The Society of Diagnostic Medical Sonography (SDMS) defines sonography as diagnostic medical procedure that uses high frequency sound waves (ultrasound) to produce dynamic visual images of organs, tissues, or blood flow inside the body. This type of procedure is often referred to as a sonogram or ultrasound scan.
Division 4: Public Service, Health, & Behavioral Sciences. Christina Hagerty, Ed.D. Diagnostic Medical Sonography is an imaging modality used to evaluate the body for diagnostic purposes. Sonographers use special equipment to direct high frequency sound waves into areas of the body.