Background and Identification
Medical ultrasound (also called diagnostic sonography or ultrasonography) is a diagnostic imaging technique or therapeutic application of ultrasound. Ultrasound is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs. Ultrasound is used to find a source of a disease or to exclude pathology. Examining pregnant women using ultrasound is called obstetric ultrasound and was an early application of clinical ultrasonography.
Ultrasounds are sound waves with frequencies much higher than those audible to humans (>20,000 Hz). Ultrasonic images (also called sonograms) are produced by sending pulses of ultrasound waves into tissue using a probe. The ultrasound pulses echo off of tissues with different reflection properties and are recorded and ultimately displayed as a visible image. Ultrasound machines generally include a video monitor to display the produced images.
Ultrasound has several advantages over other dominant methods of medical imaging including the ability to produce images in real-time and portability. Ultrasound machines are also less expensive than other imaging modalities and do not use harmful ionizing radiation.
Hitachi Healthcare is a Japanese medical product manufacturer that specialized in ultrasound systems. Hitachi Healthcare developed the world’s first commercially available diagnostic ultrasound system in 1960. Aloka Co. Ltd. merged with Hitachi, so the company is sometimes referred to as Hitachi Aloka. Hitachi Aloka ultrasound systems typically include the name “Hitachi” in capital letters in the center of the machine’s digital screen.