Fetal ultrasound

Mechanical effects

Melvin E. Stratmeyer, James F Greenleaf, Diane Dalecki, Kjell A. Salvesen

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

In this discussion, any biological effect of ultrasound that is accompanied by temperature increments less than 1°C above normal physiologic levels is called a mechanical effect. However, one should keep in mind that the term mechanical effect also includes processes that are not of a mechanical nature but arise secondary to mechanical interaction between ultrasound and tissues, such as chemical reactions initiated by free oxygen species generated during cavitation and sonoluminescence. Investigations with laboratory animals have documented that pulsed ultrasound can produce damage to biological tissues in vivo through nonthermal mechanisms. The acoustic output used to induce these adverse bioeffects is considerably greater than the output of diagnostic devices when gas bodies are not present. However, low-intensity pulsed ultrasound is used clinically to accelerate the bone fracture repair process and induce healing of nonunions in humans. Low-intensity pulsed ultrasound also has been shown to enhance repair of soft tissue damage and accelerate nerve regeneration in animal models. Although such exposures to low intensity do not appear to cause damage to exposed tissues, they do raise questions about the acoustic threshold that might induce potentially adverse developmental effects in the fetus. To date, bioeffects studies in humans do not substantiate a causal relationship between diagnostic ultrasound exposure during pregnancy and adverse biological effects to the fetus. However, the epidemiologic studies were conducted with commercially available devices predating 1992, having outputs not exceeding a derated spatial-peak temporal-average intensity (I SPTA.3) of 94 mW/cm 2. Current limits in the United States allow an I SPTA.3 of 720 mW/cm 2 for obstetric modes. At the time of this report, available evidence, experimental or epidemiologic, is insufficient to conclude that there is a causal relationship between obstetric diagnostic ultrasound exposure and adverse nonthermal effects to the fetus. However, low-intensity pulsed ultrasound effects reported in humans and animal models indicate a need for further investigation of potentially adverse developmental effects.

Original languageEnglish (US)
Pages (from-to)597-605
Number of pages9
JournalJournal of Ultrasound in Medicine
Volume27
Issue number4
StatePublished - Apr 2008

Fingerprint

Fetus
fetuses
Acoustics
Obstetrics
Ultrasonography
animal models
biological effects
Animal Models
damage
Equipment and Supplies
Nerve Regeneration
output
Bone Fractures
Laboratory Animals
sonoluminescence
Epidemiologic Studies
acoustics
Gases
pregnancy
healing

Keywords

  • Fetus
  • Mechanical effects
  • Obstetrics
  • Ultrasound

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology
  • Acoustics and Ultrasonics

Cite this

Stratmeyer, M. E., Greenleaf, J. F., Dalecki, D., & Salvesen, K. A. (2008). Fetal ultrasound: Mechanical effects. Journal of Ultrasound in Medicine, 27(4), 597-605.

Fetal ultrasound : Mechanical effects. / Stratmeyer, Melvin E.; Greenleaf, James F; Dalecki, Diane; Salvesen, Kjell A.

In: Journal of Ultrasound in Medicine, Vol. 27, No. 4, 04.2008, p. 597-605.

Research output: Contribution to journalArticle

Stratmeyer, ME, Greenleaf, JF, Dalecki, D & Salvesen, KA 2008, 'Fetal ultrasound: Mechanical effects', Journal of Ultrasound in Medicine, vol. 27, no. 4, pp. 597-605.
Stratmeyer ME, Greenleaf JF, Dalecki D, Salvesen KA. Fetal ultrasound: Mechanical effects. Journal of Ultrasound in Medicine. 2008 Apr;27(4):597-605.
Stratmeyer, Melvin E. ; Greenleaf, James F ; Dalecki, Diane ; Salvesen, Kjell A. / Fetal ultrasound : Mechanical effects. In: Journal of Ultrasound in Medicine. 2008 ; Vol. 27, No. 4. pp. 597-605.
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