Medical ultrasonography

Medical ultrasonography or sonography is an ultrasound-based diagnostic imaging technique used to visualize muscles and internal organs, their size, structure and any pathological lesions, making them useful for scanning the organs. Obstetric sonography is commonly used during pregnancy.

The choice of frequency is a trade-off between the image spatial resolution and the penetration depth into the patient. Typical diagnostic sonography scanners operate in the frequency range of 2 to 13 megahertz.Whilst in physics the term "ultrasound" applies to all acoustic energy with a frequency above human hearing 20,000 Hertz,its common usage as a term of medical imaging applies to just a band of frequencies hundreds of times higher.