Editing Ultrasound (section)

==Imaging==
[[File:Embryo at 14 weeks profile.JPG|thumb|right|[[Obstetric ultrasonography|Sonogram]] of a fetus at 14 weeks (profile)]]
[[File:How Ultrasound Imaging Works (Sonography).webm|thumb|thumbtime=48|An explanatory video about medical ultrasound technology by the U.S. [[National Institute of Biomedical Imaging and Bioengineering]].]]
[[File:3dultrasound.png|thumb|right|Head of a fetus, aged 29 weeks, in a "[[3D ultrasound]]"]]
The potential for ultrasonic imaging of objects, in which a 3&nbsp;GHz sound wave could produce resolution comparable to an optical image, was recognized by Sergei Sokolov in 1939. Such frequencies were not possible at the time, and what technology did exist produced relatively low-contrast images with poor sensitivity.<ref name=EPP99/>
Ultrasonic imaging uses frequencies of 2 megahertz and higher; the shorter wavelength allows resolution of small internal details in structures and tissues. The power density is generally less than 1 watt per square centimetre to avoid heating and cavitation effects in the object under examination.<ref name=Betts00/> Ultrasonic imaging applications include industrial nondestructive testing, quality control and medical uses.<ref name=EPP99>{{cite book | veditors = Papadakis EP | title = Ultrasonic Instruments & Devices | publisher = Academic Press | date = 1999 | isbn = 978-0-12-531951-5 | page = 752 }}</ref>

===Acoustic microscopy===
[[Acoustic microscopy]] is the technique of using sound waves to visualize structures too small to be resolved by the human eye. High and ultra high frequencies up to several gigahertz are used in acoustic microscopes. The reflection and diffraction of sound waves from microscopic structures can yield information not available with light.

===Human medicine===
[[Medical ultrasound]] is an ultrasound-based diagnostic [[medical imaging]] technique used to visualize muscles, tendons, and many internal organs to capture their size, structure and any pathological [[lesion]]s with real time tomographic images. Ultrasound has been used by [[radiologist]]s and [[sonographer]]s to image the human body for at least 50 years and has become a widely used diagnostic tool.<ref>{{Cite journal |last1=Rathbun |first1=Kimberly M. |last2=Patel |first2=Arjun N. |last3=Jackowski |first3=Jacob R. |last4=Parrish |first4=Matthew T. |last5=Hatfield |first5=Ryan M. |last6=Powell |first6=Tyler E. |date=2023-04-19 |title=Incorporating ultrasound training into undergraduate medical education in a faculty-limited setting |journal=BMC Medical Education |volume=23 |issue=1 |pages=263 |doi=10.1186/s12909-023-04227-y |doi-access=free |issn=1472-6920 |pmc=10113991 |pmid=37076831}}</ref> The technology is relatively inexpensive and portable, especially when compared with other techniques, such as [[magnetic resonance imaging]] (MRI) and [[computed tomography]] (CT). Ultrasound is also used to visualize fetuses during routine and emergency [[prenatal care]]. Such diagnostic applications used during [[pregnancy]] are referred to as [[Obstetric ultrasonography|obstetric sonography]]. As currently applied in the medical field, properly performed ultrasound poses no known risks to the patient.<ref>{{cite journal | vauthors = Hangiandreou NJ | title = AAPM/RSNA physics tutorial for residents. Topics in US: B-mode US: basic concepts and new technology | journal = Radiographics | volume = 23 | issue = 4 | pages = 1019–33 | year = 2003 | pmid = 12853678 | doi = 10.1148/rg.234035034 }}</ref> Sonography does not use [[ionizing radiation]], and the power levels used for imaging are too low to cause adverse heating or pressure effects in tissue.<ref>{{Cite web|url=https://www.fda.gov/radiation-emittingproducts/radiationemittingproductsandprocedures/medicalimaging/ucm115357.htm|title=Medical Imaging{{Snd}} Ultrasound Imaging| author = Center for Devices and Radiological Health |website=www.fda.gov|language=en|access-date=2019-04-18}}</ref><ref>{{cite journal | vauthors = Ter Haar G | title = Ultrasonic imaging: safety considerations | journal = Interface Focus | volume = 1 | issue = 4 | pages = 686–97 | date = August 2011 | pmid = 22866238 | pmc = 3262273 | doi = 10.1098/rsfs.2011.0029 }}</ref> Although the long-term effects due to ultrasound exposure at diagnostic intensity are still unknown,<ref>{{cite web | url = https://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm115357.htm | title = FDA Radiological Health{{Snd}} Ultrasound Imaging | archive-url = https://web.archive.org/web/20150703170404/https://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm115357.htm |archive-date = 2015-07-03 | publisher = United States Food and Drug Administration | date = 2011-09-06 | access-date = 2011-11-13 }}</ref> currently most doctors feel that the benefits to patients outweigh the risks.<ref>{{cite web | url = http://www.aium.org/patient/aboutexam/safety.asp | archive-url = https://web.archive.org/web/20070221101616/http://www.aium.org/patient/aboutexam/safety.asp | archive-date = 2007-02-21 | title = Patient Information{{Snd}} Ultrasound Safety | publisher = American Institute of Ultrasound in Medicine }}</ref> The ALARA (As Low As Reasonably Achievable) principle has been advocated for an ultrasound examination{{Snd}} that is, keeping the scanning time and power settings as low as possible but consistent with diagnostic imaging{{Snd}} and that by that principle nonmedical uses, which by definition are not necessary, are actively discouraged.<ref>{{cite web | url = http://www.aium.org/resources/guidelines.aspx | title = American Institute for Ultrasound in Medicine practice guidelines | archive-url = https://web.archive.org/web/20150701090209/http://www.aium.org/resources/guidelines.aspx | archive-date = 2015-07-01 | publisher = American Institute for Ultrasound in Medicine | access-date = 2015-07-01 }}</ref>

Ultrasound is also increasingly being used in trauma and first aid cases, with [[emergency ultrasound]] being used by some EMT response teams. Furthermore, ultrasound is used in remote diagnosis cases where [[teleconsultation]] is required, such as scientific experiments in space or mobile sports team diagnosis.<ref>{{cite web | url = http://www.epiphan.com/solutions_new/?arid=1082 | title = DistanceDoc and MedRecorder: New Approach to Remote Ultrasound Imaging Solutions | publisher = Epiphan Systems | archive-url = https://web.archive.org/web/20110214122805/http://www.epiphan.com/solutions_new/?arid=1082 | archive-date = 2011-02-14 }}</ref>

According to RadiologyInfo,<ref>{{cite web|url=http://www.radiologyinfo.org/en/info.cfm?pg=pelvus&bhcp=1|title=Ultrasound Imaging of the Pelvis|work=radiologyinfo.org|access-date=2008-06-21|archive-url=https://web.archive.org/web/20080625070931/http://www.radiologyinfo.org/en/info.cfm?pg=pelvus&bhcp=1|archive-date=2008-06-25|url-status=live}}</ref> ultrasounds are useful in the detection of [[human pelvis|pelvic]] abnormalities and can involve techniques known as [[Abdomen|abdominal]] (transabdominal) ultrasound, [[vagina]]l (transvaginal or endovaginal) ultrasound in women, and also [[Rectum|rectal]] (transrectal) ultrasound in men.

=== Veterinary medicine ===
{{See also|Preclinical imaging}}
Diagnostic ultrasound is used externally in horses for evaluation of soft tissue and tendon injuries, and internally in particular for reproductive work{{Snd}}evaluation of the reproductive tract of the mare and pregnancy detection.<ref>{{cite web | vauthors = Pycock JF | title = Ultrasound characteristics of the uterus in the cycling mare and their correlation with steroid hormones and timing of ovulation | url = http://www.equine-reproduction.com/articles/ultrasound-steroids.shtml | archive-url = https://web.archive.org/web/20090131144526/http://equine-reproduction.com/articles/ultrasound-steroids.shtml | archive-date = 31 January 2009 }}</ref> It may also be used in an external manner in stallions for evaluation of testicular condition and diameter as well as internally for reproductive evaluation (deferent duct etc.).<ref>{{cite book | vauthors = McKinnon AO, Voss JL | title = Equine Reproduction | publisher = Lea & Febiger | date = 1993 | isbn = 978-0-8121-1427-0 }}</ref>

By 2005, ultrasound technology began to be used by the beef [[cattle]] industry to improve animal health and the yield of cattle operations.<ref name=SubiacoDeltaFarm>{{cite web
 |url=http://deltafarmpress.com/news/050520-subiaco-angus/
 |title=Subiaco Abbey's Angus herd
 |vauthors = Bennett D
 |date=May 19, 2005
 |work=Delta Farm Press
 |archive-url=https://web.archive.org/web/20070404221048/http://deltafarmpress.com/news/050520-subiaco-angus/
 |archive-date=April 4, 2007
 |access-date=February 27, 2010 }}</ref> Ultrasound is used to evaluate fat thickness, rib eye area, and intramuscular fat in living animals.<ref name=WVUWagner>{{cite web
 |url         = http://www.caf.wvu.edu/~forage/breeding/cattlebr.htm
 |title       = Extension Effort in Beef Cattle Breeding & Selection
 |vauthors     = Wagner W
 |work        = [[West Virginia University]] Extension Service
 |archive-url  = https://web.archive.org/web/20081214174609/http://www.caf.wvu.edu/~forage/breeding/cattlebr.htm
 |archive-date = December 14, 2008
 |access-date  = February 27, 2010
 }}</ref> It is also used to evaluate the health and characteristics of unborn calves.

Ultrasound technology provides a means for cattle producers to obtain information that can be used to improve the breeding and husbandry of cattle. The technology can be expensive, and it requires a substantial time commitment for continuous data collection and operator training.<ref name=WVUWagner /> Nevertheless, this technology has proven useful in managing and running a cattle breeding operation.<ref name=SubiacoDeltaFarm />