Nonionizing ultrasonic radiation penetrates biological soft tissues. Ultrasound that is scattered, attenuated and Doppler‐frequency‐shifted by tissues and contrast agents can be detected and processed safely to create one‐, two‐ and three‐dimensional images of structure and function, often in real time.

Keywords: imaging; pulse‐echo; Doppler; bioeffects; function; structure

Figure 1.

Diagram showing the general principles of ultrasonic imaging.

Figure 2.

Ultrasonic scanning in progress.

Figure 3.

Ultrasonic colour flow image of blood vessels in the neck, showing stenosis of the internal carotid artery by an atherosclerotic plaque.

Figure 4.

Three‐dimensional ultrasonic scan of a 12‐week fetus in utero.



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Further Reading

Evans DH, McDicken WN, Skidmore R and Woodcock JP (1989) Doppler Ultrasound: Physics, Instrumentation and Clinical Applications. Chichester, UK: Wiley.

Fish P (1990) Physics and Instrumentation of Diagnostic Medical Ultrasound. Chichester, UK: Wiley.

ter Haar G and Duck FA (2000) The Safe Use of Ultrasound in Medical Diagnosis. London: British Medical Ultrasound Society/British Institute of Radiology.

Holm HH and Skjoldbye B (1996) Interventional ultrasound. Ultrasound in Medicine and Biology 22: 773–789.

McGahan, JP and Goldberg BB (eds) (1997) Diagnostic Ultrasound: A Logical Approach. Philadelphia, PA: Lippincott‐Raven.

Taylor KJW, Burns PN and Wells PNT (eds) (1995) Clinical Applications of Doppler Ultrasound, 2nd edn. New York: Raven Press.

Wells PNT (1977) Biomedical Ultrasonics. London: Academic Press.

Wells PNT (1978) History. In: de Vlieger M, Holmes JH and Kazner E et al. (eds) Handbook of Clinical Ultrasound, pp. 3–13. New York: Wiley.

Wells PNT (1997) Sound waves: ultrasonography. In: van Schulthess GK and Hennig J (eds) Functional Imaging, pp. 433–463. Philadelphia, PA: Lippincott‐Raven.

Wells PNT (1999) Ultrasonic imaging of the human body. Reports on Progress in Physics 62: 671–722.

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Wells, Peter NT(Sep 2005) Ultrasound. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0004076]