The modern era of ultrasound detectors began in the late 1960s. Today, millions of parents-to-be show off pictures of babies still in the womb, but Diagnostic Medical Sonography has broader applications. The technology is used in evaluating heart function, assessing blood flow to carotid arteries and examining organs of the abdominal cavity. The use of sound waves in medical diagnosis has its roots in the development of naval sonar, radar and specialized equipment that detected flaws in metal. A doctor at the Naval Medical Research Institute in the late 1940s used metal flaw detectors and naval sonar to find gall bladder stones. That is considered the first diagnostic use.
Did You Know?
- Translating sound into an image takes three steps: sound wave production, echo reception and echo interpretation.
- Echo interpretation includes three components: direction, strength and duration between transmission and reception. With that information, scanners can create images.
- The term "ultrasound" in physics applies to all acoustic energy with a frequency above human hearing (20 kilohertz). Typical diagnostic sonographic scanners use frequencies of 2 to 18 megahertz, hundreds of times greater.
- Lower frequencies produce less resolution but create images deeper into the body.
- Doppler ultrasonography uses colors to evaluate blood flow and muscle motion. A leaky heart valve will produce a flash of a specific color.
- Sonography can produce images of muscle and soft tissue well but sonographic devices have a hard time penetrating bone.
- Scientists in Sweden made the first successful measurement of heart activity in 1953 using a device borrowed from a ship construction.
- The scientific lineage of sonography predates naval and marine applications. It started in the 19th century with the Curie brothers' studies of the properties of crystals.