2010 Group Project 1

2010-09-23T01:21:20Z

Z3305561: /* Current Research and Future Uses in Prenatal Diagnosis */

[[File:ZUltrasound Image of Fetal Aorta.jpg| right]]
=Ultrasound=

==Introduction==

Today, ultrasound is known to almost everyone in the developed world as the "normal" prenatal examination that pregnant women undergo to assess the development of their pregnancy. Ultrasound scans reveal the size and position of the fetus, its sex, approximate gestational age, the number of fetuses, and generally useful information to chart the progress of the growing fetus. Ultrasound can also be of great help in the prenatal diagnosis of structural abnormalities, revealing before birth physical developmental defects such as cleft lip or abnormal limb growth and allowing parents and physicians to prepare for these situations and make early decisions about important issues such as termination and treatment.

==History Time Line==

Interest and research into ultrasound began as early as the 1700’s and had been developing continuously until now. It has transformed from a simple piece of machinery which was mainly used for navigation in World war I and as a powerful locator for ships and seafaring vessels to a more complex machine in modern times, and is now used as a main prenatal diagnostic tool. Generating heat for patient therapy was initially the main use of ultrasound in the medical field, but it was later developed into a therapeutic tool (e.g. using vibrations to stimulate regrowth of bone in immobilised fractures) and more recently has become important in prenatal diagnosis, as well as in the diagnosis of diseases and injuries. <ref name="website">Woo, Joseph (2002) A short history of the development of ultrasound in obstetrics and gynecology. Accessed 13/9/2010<http://www.ob-ultrasound.net/history1.html></ref>

The following time-line briefly highlights some of the important discoveries in relation to ultrasound.

*'''1794'''- Lazzaro Spallanzani proposed that bats use hearing rather than sight to move with the aid of "high-frequency ultrasound"

*'''1880'''- Pierre Curie and Jacques Curie asserted the piezoelectric effect which lead to the creation of the transducer

*'''1826'''-Jean Daniel Colladon successfully measured the speed of sound underwater

*'''1914'''-Reginald Fessenden created the first operating sonar system to detect ice bergs underwater

*'''1920'''-Paul Langévin used ultrasound for clinical therapy

*'''1938'''- Raimar Pohlman demonstrated the therapeutic uses of ultrasound by creating ultrasonic physiotherapy

*'''1942'''- Lynn and Putnam destroyed brain cells using ultrasound waves

*'''1963'''- Donald and MacVicar detected the gestational sac of the embryo using ultrasound

*'''1972''' -Hugh Robinson used ultrasound to detect fetal heart beats and crown-to-rump length

*'''1973'''- George Radovanovitch and David Carpenter created grey-scale images of prenatal embryos

*'''1965'''- Walter Krause and Richard Soldner created real time scanner which can capture 15 images per second

*'''1984'''- Kazunori Baba first invented 3-D ultrasound

*'''1996'''- Nelson researches on 4-D (motion 3-D) fetal echocardiography<ref name="website"></ref>

Link for more history | [http://www.ob-ultrasound.net/history1.html History of Ultrasound]

==How It Works==

The basic principle of ultrasound is similar to that of sonar – that is, sending out pulses of high-frequency sound waves, receiving back the echoes of those waves after they bounce off surrounding materials, and constructing a picture of those materials from the received sounds. In medical ultrasound, or sonography, pulses of ultrasound are repeatedly sent into the body where they bounce off the edges of organs and tissues, relaying that anatomical information back to the ultrasound machine. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp3-5</ref>

'''There are three main elements in an ultrasound system: the transducer, the machine and the recording devices''' <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 28-31</ref>.

====The Transducer====

The transducer is the piece of equipment in contact with the patient. It emits the ultrasound pulses and receives the echoes of those pulses. Information about the patient’s tissues is generated by calculating the time it takes for the ultrasound pulses to scatter and bounce off those tissues and travel back to the transducer. The ultrasound waves will take longer or shorter amounts of time to travel through different tissues depending on their properties.

Since air diminishes the integrity of the ultrasound signals (the ultrasound can bounce off even a thin layer of air, almost completely preventing the penetration of the ultrasound into the patient’s tissues), a medium such as a water-soluble gel is applied between the transducer and the patient’s skin to improve the interface between the two. There are several kinds of transducers producing different kinds of ultrasound images, discussed below. Transducers can be non-invasive (for prenatal diagnosis, pressed against the woman's pelvis or abdomen) or they can be invasive (transvaginal transducers, for example, are inserted into the vagina to obtain better views of the ovaries, fallopian tubes, uterus, and surrounding structures).

[[File:ZScan_Lines.jpg|thumb|right|Diagram showing a single scan line on the left and an image comprised of many scan lines on the right]]
Within the transducer are elements made of silicon crystals. The pulses of ultrasound are created using the piezoelectric effect – when silicon crystals experience electrical impulses they mechanically deform on a microscopic level, producing high-frequency sound waves. Returning sound waves (echoes) will similarly deform the silicon crystals, and these deformations are converted to electrical impulses which are then sent to the ultrasound machine for processing. Different kinds of transducers will produce different kinds of images, or scans. High-frequency transducers (5MHz or greater) give better resolution of images, but low frequency transducers penetrate deeper into tissues and so provide images of deeper structures. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 28-31</ref>

Sending one ultrasound pulse into the body will generate a line of dots – this represents one line of echo information, or one scan line. Not all of that pulse bounces back off one single anatomical structure; instead, most of the pulse continues through to deeper structures where some of the pulse bounces back from each structure it passes through. This is what generates the line of dots representing an internal view of the patient. Since the echoes of a single pulse generate one scan line of information, generating several scan lines next to one another in an ordered sequence will generate a cross-sectional image of the patient (see the diagram on the right). This way of directing pulses through the tissues is termed “scanning” or “sweeping”. Scanning is performed quickly and automatically by an “array” of organised group of transducer elements, creating many still images or frames which are viewed in sequence, like a movie. Thus, ultrasound exams are performed in real-time. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp3-9</ref>

Different transducers have different arrays of piezoelectric elements, and produce a variety of different scans or images:

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Types of Transducers and Scans'''
|-
! style="background: yellow; color: black" | Linear Array Transducers
! style="background: green; color: white" | Curved or Convex Array Transducers
! style="background: blue; color: white" | Phased Array Transducers
|-
| Elements are arranged in a straight line, firing pulses vertically and parallel to each other
| Elements are arranged nest to each other in a convex shape, emitting pulses in a sunburst-like manner
| Emit pulses from a compact line of elements in slightly different directions in rapid sequence
|-
| The kind of image formed is called a linear or rectangular scan
| The kind of image formed is a sector or modified sector scan
| The kind of image formed is a sector scan
|-
| align="center" width="150" | [[File:ZLinear_Array_Transducer.jpg|200px]]
| align="center" width="150" | [[File:ZConvex_Array_Transducer.jpg|350px]]
| align="center" width="150" | [[File:ZPhased_Array_Transducerki.jpg|200px]]
|}

====The Ultrasound Machine and Recording Devices====
[[File:ZUltrasound_Image_of_Fetal_Aorta.jpg|thumb|right|2D ultrasound image of a sagittal section of a fetal chest, showing the typical greyscale appearance of ultrasound images]]

The ultrasound machine itself is comprised of the computer hardware and software needed to convert the signals picked up by the transducer into an image that can be viewed. The image is in greyscale, using various shades from black to white to indicate different tissues and tissue features.

The other basic part of the ultrasound system is the recording equipment – that is, a range of devices such as multiformat cameras, video printers and video recorders used to store information from the patient’s examination.

So far, what has been explained are the basic principles of how a normal 2D ultrasound image is generated. There have been are, however, some developments in ultrasound technology that allow the generation of slightly different images to the normal 2D ones, providing more diagnostic information. These are the Doppler ultrasound and 3D ultrasound imaging.

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

===Doppler Ultrasound===
[[File:ZDoppler_Image_of_Fetal_Aorta.jpg|thumb|left|Colour Doppler ultrasound image showing a saggital section of the aortic arch and descending aorta of the fetus]]

Doppler ultrasound utilises the Doppler effect to view moving structures, such as the flow of blood through major blood vessels of the heart. The Doppler effect refers to the change in frequency of a wave relative to the motion of the wave source and the observer. In a Doppler ultrasound, sound waved are reflected from moving structures with a shift in frequency of those sound waves proportional to the velocity of the moving structure.<ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 30</ref>

Continuous-wave Doppler ultrasound detects signals from anything moving in the path of the pulse, and cannot distinguish well between separate vessels. Pulsed Doppler ultrasound uses a pulse in a thin, focused beam and detects signals from only one point in that beam, allowing the imaging of specific vessels. Colour Doppler imaging is a type of pulsed Doppler ultrasound where software is used to overlay the greyscale image with colours representing frequency shifts. Different colours are assigned to indicate movement towards or away from the transducer. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp 185-186</ref><ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 30</ref>

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

Link to video of the Doppler Effect | [http://videos.howstuffworks.com/discovery/27963-assignment-discovery-doppler-effect-video.htm Assignment Discovery: the Doppler Effect]

===3D Ultrasound===
[[File:Z3DCleft_Lip_Picture.jpg|thumb|right|3D ultrasound image showing a fetus with a cleft lip abnormality]]

Three-dimensional ultrasound images are produced in one of several ways. The first is to have several arrays of 2D transducers working together to collect a series of 2D cross-sections and combine these into a 3D image, though this can be difficult. 3D ultrasound images can also be made with the use of arrays of 1D transducers to create 2D B-scan images of known areas in 3D space. The 1D arrays can either by swept across the patient by machine or by the technician. 3D ultrasound images are particularly useful for visualising the volumes of structures, and better viewing complex 3D structures. However, even today it is mostly 2D ultrasound that is used, with 3D ultrasound only used in select applications. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp. 6</ref><ref><pubmed>20349815</pubmed></ref>

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

Link to a review of 3D ultrasound imaging | [http://www.ncbi.nlm.nih.gov/pubmed/20349815 Three-dimensional ultrasound imaging]

==Current Uses in Prenatal Diagnosis==

Ultrasound imaging is an effective non-invasive technique currently used in three main capacities in terms of prenatal diagnosis: guiding invasive tests, detecting abnormalities in at-risk patients, and as a widely-used screening test for abnormalities in the general population during the second trimester of pregnancy.

===Guiding Invasive Procedures===

Invasive procedures for detecting abnormalities such as amniocentesis and chorionic villus sampling have become safer with the guidance of ultrasound, as the physician is no longer operating “blind”. The ultrasound machine can show in real-time the movement and position of the needle, reducing the risk of damage to surrounding anatomical structures. <ref>Anderson, J.C. (1995) Amniocentesis, chorionic villus sampling and fetal blood sampling. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 28-31</ref>

Furthermore, if these invasive tests guided by ultrasound reveal that the patient is a high-risk for fetal abnormalities, a high resolution ultrasound can then be employed to attempt to visually diagnose potential structural abnormalities.

===Diagnosis of Abnormalites===

Ultrasound can be used to detect the three main groups of fetal abnormalities: neural tube defects, chromosomal defects and congenital heart abnormalities. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 31</ref>

====Neural Tube Defects====

These are a relatively common assembly of structural abnormalities, some of which are spina bifida, anencephaly, and encephalocoele. If serum examinations of the maternal alpha-fetoprotein level reveal it to be high ultrasound imaging can be used to guide the needle for invasive but more specific tests such as amniocentesis, as well as to define the gestational age of the fetus. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 31</ref> Ultrasound imaging of the cranium is also a diagnostic test for neural tube defects, and rates detection of spina bifida with ultrasound have been relatively high with high-quality ultrasound systems. <ref>Tyrell, S., Howell, D., Bark, M. Allibone, E. and Lilford, R.J. (1988) Should alpha-fetoprotein estimation be carried out in centres where ultrasound screening is routine? A sensitivity analysis approach. ‘’American Journal of Obstetrics and Gynecology’’ 158: 1092-9</ref> In open neural tube defects, decreased hydrostatic pressure in the spinal canal causes the cerebellum to take on a “V”-like shape as well as causing ‘bossing’ of the frontal bones (the ‘lemon sign’), and in some cases dilation of ventricles. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 32</ref> Ultrasound imaging of the spine in transverse, coronal and sagittal planes may also reveal defects, including closed defects which may not lead to the diagnostic high alpha-fetoprotein levels in the amniotic fluid.

Women at high risk for neural tube defects (those with a family history, Type 1 Diabetes, and those on some medications) should always be referred for prenatal ultrasound examination to screen for the defects.

====Chromosomal Abnormalities====

Chromosomal anomalies appear in approximately 1% of pregnancies lasting beyond 20 weeks, a great number of which are not associated with any significant structural defects, and about 40% of miscarriages are linked to chromosome abnormalities in the fetus<ref>Young, I.D. (1992) Inceidence and genetics of congenital malformations. In “Prenatal Diagnosis and Screening,’’ ed. DJH Brock, C.H Rodeck and M.A. Ferguson-Smith, pp. 171-87. Edinburgh: Churchill Livingstone.</ref>. Autosomal trisomies contribute to about half of that 40%, with the most common being trisomies 13, 18 and 21. Where trisomies 13 and 18 are generally lethal trisomy 21 or Down Syndrome is not; however, it does cause some structural malformation and impaired intellectual ability.

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Common Ultrasound Findings For Specific Trisomies <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 40-43</ref> '''
|-
! style="background: yellow; color: black" | Trisomy 21
! style="background: green; color: white" | Trisomy 18
! style="background: blue; color: white" | Trisomy 13
|-
| Duodenal atresia
| Exomphalos
| Craniofacial defects in the midline of the face
|-
| Significant cardiac defects (such as atrioventricular canal defects)
| Enlargement of cisterna magna
|}

There are two main clusters of symptoms caused by autosomal trisomies that can be detected with ultrasound, major and minor signs. The major signs have a high predictability for trisomies, but are not often seen. Minor signs are fairly indicative of trisomies but can also be seen in unaffected fetuses.

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Major and Minor Signs of Trisomies <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 36</ref> '''
|-
! style="background: yellow; color: black" | Major Signs
! style="background: green; color: white" | Minor Signs
|-
| Cystic hygroma (congenital lymphatic lesion)
| Brachycephaly ("flat head")
|-
| Significant cardiac defects (such as atrioventricular canal defects)
| Cysts of choroid pleuxs
|-
| Duodenum without orifice or absent
| Shortened humerus and/or femur
|-
| Exomphalos (weakening of the abdominal wall at the join of the umbilicus)
| Clinodactyly (curvature of the 5th finger away from the midline)
|-
| Ventriculomegaly
| Nuchal fold larger than 6 mm
|-
| Craniofacial defects in the midline
| Absent/hypoplastic fifth middle phalanx
|-
|
| Widely-spaced toes
|-
|
| Pyelectasis (dilation of the pelvis of the kidney)
|}

====Congenital Heart Abnormalities====

Relatively common abnormalities, these could affect up to 1% of fetuses. Though a great number are asymptomatic, some – like a hypoplastic left ventricle – can be life-threatening. With the introduction of Doppler ultrasound, physicians now can study the flow of blood in the fetus, which has had a significant impact on the prenatal diagnosis of heart valve defects – if blood can be seen passing through valves that should be sealed closed, that indicates an abnormality, and vice versa.

To diagnose heart defects, the ultrasound examiner first obtains a single view of the four chambers of the heart. One problem is that some of these defects may not be visible at 18-20 weeks, the general time for an ultrasound screening examination to be administered. If a defect is detected, the fetus is often also tested for chromosomal abnormalities, since the two are often linked. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 40</ref>

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Heart Defects That Can Be Detected By Ultrasound With A Four-Chamber View Of The Heart <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 42</ref>'''
|-
! Pulmonary or aortic atresia
| A malformation of the pulmonary or aortic valves in which the opening fails to form, meaning the valves obstruct the blood flow to the lungs or aorta
|-
! Double inlet ventricle
| The left or right ventricle has two separate atrioventricular openings and valves
|-
! Ebstein anomaly
| The improper placement of the tricuspid valve further toward the apex of the heart, resulting in a large right atrium and small right ventricle
|-
! Large ventricular septal defect
| A large hole in the septum between the left and right ventricles of the heart, resulting in shunting of blood from the left to the right ventricle; can be fatal
|-
! Atrioventricular canal defect
| A malformation of the atrioventricular septum of the heart
|}

====Other Abnormalities====

Ultrasound can be used to detect a vast number of structural defects in any area of the fetal anatomy.

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Some Structural Defects Diagnosed By Ultrasound <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 41-50</ref>'''
|-
! Facial defects
| Cleft lip
| This can also be more clearly visualised with the use of 3D ultrasound imaging to indicate the extent of the malformation<ref>Wayne, C., Cook, K., Sairam, S., Hollis, B., Thilaganathan, B. (2002) Sensitivity and accuracy of routine antenatal ultrasound screening for isolated facial clefts. ‘’British Journal of Radiology,’’ 75: 584-589</ref>
|-
! Intracranial abnormalities
| Hydrocephalus
| Indicated by the transverse measurement of the atrium of the lateral ventricle being larger than 1cm
|-
! Thoracic abnormalities
| Diaphragmatic hernia
| Visible in a sagittal section, where an abdominal organ has herniated through the diaphragm to sit in the thoracic cavity, can compress lung/s
|-
! Gastrointestinal defects
| Gastroschisis
| The intestines and/or abdominal organs develop outside the abdomen, visible upon examination as a mass on the abdomen separate from the umbilical cord
|-
! Skeletal defects
| Osteogenesis imperfecta
| A brittle bone syndrome which may be recognised by ultrasound imaging showing shortening and bowing of long bones (femurs, humerus and tibia)
|}

===Normal Prenatal Screening===

Ultrasound scans are widely used in the second trimester (weeks 18-20) to screen for any structural abnormalities in the developing fetus. This is useful for detecting abnormalities in fetuses in patients considered low-risk (e.g. with no history of affected children or no family history of birth defects) who would not otherwise consider that their fetus may have a physical developmental issue.

It is important to note that whilst in the diagnosis of fetal abnormalities in patients suspected of having said abnormalities, ultrasound imaging can be more specific in that the sonographer or sonologist knows that they are looking for, and be more specific in their examination (i.e. focus on particular anatomical areas, collecting several images of the structure in question). As a screening tool, however, less obvious defects like small ventricular septal defects are easy to miss during a broad, non-focused examination, even if the ultrasound technician does obtain an image of the chambers of the heart. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 32</ref>

==Risks and Regulations==

Epidemiological studies have not indicated any identifiable risks associated with the use of ultrasound as a diagnostic tool. Animal studies have indicated that only at intensities higher than expected in pertinent tissues during ultrasound imaging are any bioeffects evident. The World Health Organization has given the statement that, “the benefits of this imaging modality far outweigh any presumed risks”<ref>World Health Organization: ‘’Environmental health criteria 22: ultrasound’’, Geneva, 1982, The Organization.</ref><ref>World Health Organization: Ultrasound. In Nonionizing radiation protection, ed 2, Geneva, 1989, The Organization.</ref> As there is currently no known risk but there are known benefits of the procedure, it is considered safe, but a conservative approach should still be taken to ensure that ultrasound exams are not given unnecessarily or excessively. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp332-333</ref>

There is however a risk of misdiagnosis by the ultrasound technician, which could cause undue parental anxiety. This can, for the most part, be avoided by ensuring ultrasound operators are all sufficiently trained and experienced. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 29</ref>

==Current Research and Future Uses in Prenatal Diagnosis==

Ultrasound is currently being used in various fields for multiple purposes such as diagnosing major diseases of fetused. It is also used to detect the placental location and “vascular system”. Moreover, recent discoveries have made the mother-fetus interaction able to be visualised by being able to see the development of placenta and the changes in blood vessels during pregnancy <ref><pubmed>20034427</pubmed></ref>. Ultrasound is an important prenatal diagnostic tool because of its visual capability, making it possible to measure crown-rump length for growth and enable physicians to see both superficial and deep layers of the embryo. With modern 3-D ultrasound technology detection of morphological changes presented diseases is easily recognisable.

Another example of current research would be using ultrasound to detect the early FASD (fetal alcohol spectrum disorder) symptoms in alcoholic mothers by examining the abnormal facial features of the fetus for better prevention and treatment, since it is known to result many birth defects such as impaired growth and cognitive dysfunction<ref><pubmed>19444822</pubmed></ref>.
Previously all an ultrasound machine could do was detect the presence of a heart-beat, however the recent research shows that cardiac defects could be detected via ultrasound from as early as week 11-13 so that there would be minimal complications for both the mother and the child<ref><pubmed>16570262</pubmed></ref>.

[[File:ZFetus yawning.jpg|thumb|left|3D ultrasound image showing a fetus yawning]]

In addition, there is also a media report that claimed 3-D ultrasound shows “complex behaviors” which would be considered impossible for a neonate. These actions include yawning, sucking, smiling, crying and scratching in the womb. The findings were considered a powerful psychological tool to study behaviours in unborn infants.<ref>BBC, Scans uncover secrets of the womb. Accessed 13/9/2010<http://news.bbc.co.uk/2/hi/health/3846525.stm></ref>
For more information about the Report|[http://news.bbc.co.uk/2/hi/health/3846525.stm BBC news]

In terms of further uses, researches are aiming to develop a better resolution and more interactive ultrasound machines for better prenatal diagnosis and treatment. Today, many more diseases have been detected via ultrasound than were able to be detected previously, hence when ultrasound systems are more developed and have greater functions, fetal abnormalities would be quickly detected and potentially could be greatly reduced which would not only help save lives, but also lead to better health care.

==Links For Further Reading==

More ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

A review of 3D ultrasound imaging | [http://www.ncbi.nlm.nih.gov/pubmed/20349815 Three-dimensional ultrasound imaging]

History of ultrasound | [http://www.ob-ultrasound.net/history1.html History of Ultrasound]

An article on ultrasound diagnosis and chromosomal abnormalities | [http://www.sonoworld.com/Client/Fetus/files/aneuploidy_2nd_trimester_cardiovascular.pdf The ultrasound detection of chromosomal anomalies]

==Glossary==

'''Atresia:''' A situation in which an orifice or channel of the body is closed or not present

'''Atrioventricular canal defect:''' A malformation of the atrioventricular septum of the heart

'''B-scan:''' A way to map the body or an area of the body using a sensing device

'''Bioeffects:''' Adverse biological effects

'''Brachycephaly:''' Or “flat head”, when the coronal sutures fuse before they should, resulting in a reduced anteroposterior diameter of the cranium

'''Clinodactyly:''' Curvature of the 5th finger away from the midline across the 4th digit

'''Cystic hygroma:''' A lymphatic lesion usually present in the posterior triangle of the neck; generally benign but sometimes disfiguring

'''Diaphragmatic hernia:''' When abdominal organs herniated through the diaphragm to lie in the thoracic cavity

'''Doppler ultrasound:''' A kind of imaging utilising the Doppler principle to examine moving structures like blood flow

'''Double inlet ventricle:''' The left or right ventricle has two separate atrioventricular openings and valves

'''Ebstein anomaly:''' The improper placement of the tricuspid valve further toward the apex of the heart, resulting in a large right atrium and small right ventricle

'''Exomphalos:''' A weakness of the abdominal wall where the umbilicus joins it

'''FASD:''' Fetal alcohol spectrum disorder; a collection or spectrum of defects caused by the consumption of alcohol by the mother during pregnancy

'''Gastroschisis:''' Intestines and/or abdominal organs develop outside the body

'''Hydrocephalus:''' Colloquially known as “water on the brain” this is a condition where large amounts of cerebrospinal fluid collect in the ventricles of the brain, which can lead to increased intracranial pressure

'''Hypoplastic left ventricle:''' A condition where the left ventricle is severely underdeveloped; often fatal

'''Large ventricular septal defect:''' A large hole in the septum between the left and right ventricles of the heart, resulting in shunting of blood from the left to the right ventricle; can be fatal

'''Linear image:''' A rectangular image produced by a transducer with elements next to each other, giving off ultrasound pulses in parallel lines

'''Modified sector scan:''' A fan-shaped image with a curved top produced by a transducer with elements next to each other that also emit pulses in different directions

'''Osteogenesis imperfecta:''' A genetic brittle bone syndrome caused by mutations in genes for procollagens

'''Piezoelectric effect:''' When silicon crystals experience electrical impulses they mechanically deform on a microscopic level, producing high-frequency sound waves

'''Pulmonary or aortic atresia:''' A malformation of the pulmonary or aortic valves in which the opening fails to form, meaning the valves obstruct the blood flow to the lungs or aorta

'''Pulse-echo technique:''' A technique in ultrasound where short pulses of ultrasound are emitted into the area to be studied, and echoes are received and interpreted to give information about the internal anatomical structures by calculating the time taken for the ultrasound echoes to return to the transducer

'''Pyelectasis:''' Dilation of the pelvis of the kidney

'''Scan line:''' The line of dots representing the information from one pulse of ultrasound

'''Sonographer:''' A trained ultrasound technician

'''Sonography:''' Medical anatomical imaging using ultrasound

'''Sonologist:''' A medical practitioner who is a trained ultrasound technician

'''Sector scan:''' A fan-shaped image produced by a transducer with ultrasound pulses emitting from the same point but in different directions

'''Three-dimensional ultrasound:''' A type of imaging where a 3D rendering of the fetus in the womb is produced by one of several means

'''Transducer:''' The part of the ultrasound apparatus that is in contact with the patient; it emits the pulses and receives the echoes of ultrasound

'''Trisomy:''' Having three copies of a chromosome due to incorrect meiosis; can be fatal or cause developmental deformities or impairments

'''Ventriculomegaly:''' When the ventricles of the brain are dilated and enlarged

==References==

<references/>

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File:ZFetus yawning.jpg

2010-09-23T01:19:30Z

Z3305561: ==What am I looking at?== This is a 3D ultrasound image showing a fetus yawning. ==Image Copyright Information== Image obtained at: http://www.flickr.com/photos/mrsflinger/463582913/sizes/m/in/photostream/ Author (content provider): Mrs Flinger Imag

==What am I looking at?==

This is a 3D ultrasound image showing a fetus yawning.

==Image Copyright Information==

Image obtained at: http://www.flickr.com/photos/mrsflinger/463582913/sizes/m/in/photostream/

Author (content provider): Mrs Flinger

Image licensed under creative commons license 2.0:

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User:Z3305561

2010-09-22T23:03:41Z

Z3305561:

2010-09-21T12:16:18Z

Z3305561:

==Peer review==

Group 6 = Maternal serum alpha-fetoprotein

The project is very organised and the pictures included were very related to the text. I really liked the link too because that not only showed you did alot of research for this project but also made it outstanding. Definetly provide me with better understanding About MSAFP.

How you can improve = There are alot of words may be try to break them down into point form but other than that everything looks good --[[User:Z3305561|Navneet Ahuja]] 12:16, 21 September 2010 (UTC)

Hi Group 6, I like how you have organised the page, its easy to follow and the layout was great. The pictures helped me with understanding the sections, although maybe they could be a bit bigger. I did learn alot about Maternal serum alpha-fetoprotein from your page, Thanks!

Improvements: Under the heading MSAFP testing and the community, there is a spelling mistake. liklihood should be likelihood, and servey should be survey. The page also looks a bit like an essay, maybe for some parts you could do a few tables to make it easier to follow

--[[User:Z3265772|z3265772]] 03:45, 21 September 2010 (UTC)

I enjoyed reading this project, the layout was overall great and i liked how you put in a link to a video. It was very understandable and i was able to follow what was said throughout reading it all. It was scientific enough but easy for anyone to read.

Improvements - the pictures were a little small, so maybe enlarge them a bit. Also, maybe break the procedure section into the different steps that are taken.

--[[User:Z3291079|z3291079]] 10:20, 21 September 2010 (UTC)

{{Template:Projects10MHtalk}}

--[[User:S8600021|Mark Hill]] 00:56, 31 August 2010 (UTC) OK guys, its now time to get going with this. You need to have significant content added to all sections on your project page before this weeks lab. Still no related images or student drawn figure here.

===You need to have this updated before this weeks lab when I will be reviewing all projects.===

--[[User:S8600021|Mark Hill]] 04:52, 23 August 2010 (UTC)OK so there is some discussion here. I need the major subheadings to be added before this weeks lab and there should be some thought to the content within each section. Still no related images here.

--[[User:S8600021|Mark Hill]] 22:56, 11 August 2010 (UTC) Well group 6 where is your work that should have been done before this week's Lab?

Hey guys, ive only really done some light background research about alpha-fetaprotein testing via wiki/google/journal articles hehe :P

Anyway, i forgot to save the links i got for the journal articles ive already printed off, but i’ll stick up their titles which can be found easily, and i’ll basically summarise the info we can use from them anyway and stick it up so we can sift through it all.

The journal articles that i remembered to save links to are as follows:

First-trimester maternal serum alpha-fetoprotein as a marker for fetal chromosomal disorders - http://onlinelibrary.wiley.com/doi/10.1002/pd.1970141012/abstract

----

--[[User:S8600021|Mark Hill]] 04:54, 23 August 2010 (UTC) Here is the Pubmed link for the above paper http://www.ncbi.nlm.nih.gov/pubmed/7534926 This is how to cite it using the current website (look at the page in edit mode):

<pubmed>7534926</pubmed>

And this is how to reference it in the body of your project page.<ref><pubmed>7534926</pubmed></ref>

to appear in a reference list

<references/>

----

Amniotic fluid alpha-fetoprotein is not a useful biological marker of pregnancy outcome - http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291097-0223%28199911%2919:11%3C1031::AID-PD684%3E3.0.CO;2-7/abstract

The value of early third-trimester maternal serum alpha-fetoprotein determination - http://onlinelibrary.wiley.com/doi/10.1002/pd.1970100308/abstract

Reduced fetal hepatic alpha-fetoprotein levels in Down' s syndrome - http://onlinelibrary.wiley.com/doi/10.1002/pd.1970101108/abstract

Very low versus undetectable maternal serum alpha-fetoprotein values and fetal death - http://onlinelibrary.wiley.com/doi/10.1002/pd.1970070605/abstract

I don’t know what you guys had in mind for splitting the work etc, but as it is, im quite happy to just get info, and slowly just add info the main page as it goes and let it slowly evolve from constant editing of stuff etc. And if anyone had clashes of ideas etc, then just fix/change a section and stick it up as well and we can all just edit passages as we see fit after some discussion hehe

so you guys know what other articles im looking at, so we don’t really double up on info, are as follows:
The effectiveness of prenatal serum biomarker screening for neural tube defects in 2nd trimester pregnant women

Msaf values in type ½ diabetic patients

2nd trim. Msaf elevation and its association with adverse maternal/fetal outcome

Afp in the early neonatal period

Structure and function of afp

ps - i most likely will just play around with headings etc on the main page...and if i put info up there in point form its not really the main text, just a quick point of ref. for what info i may or may not stick up etc as well as just general format testing haha ^_^

--[[User:Z3186755|3186755]] 15:56, 14 August 2010 (UTC)

Hi everyone, yeh I think its a good idea to compile information and research before the next lab and go through
it together before we designate certain areas to one another. I'll try to get through some of the articles that
are up to get an idea of how we are going to divide the work up. Possible categories:

1) Introduction to how it is carried out, history, developements.
2) How the test works, what is used or tested.
3) What the test is looking for, diseases, syndromes, dissorders.
4) Any problems or flaws the test has, effectiveness, contempory issues.

We should discuss more in depth during the lab, put up any more ideas for subheadings that we should use.

Thanks

--[[User:Z3290040|3290040]] 12:31, 17 August 2010 (UTC)

Hey guys,

I’m still in the research stage with this assignment, I think we really need to come up with a specific outline or structure for the assignment so the work can be divided up soon.

This structure is similar to the previous one mentioned above:introduction and background information on prenatal testing, what is alpha-fetoprotein how it is made by the foetus etc, the diseases that could be tested, history of maternal alpha- fetoprotein testing, accuracy etc.I don’t think there is much information on the procedure or ethical issues on this topic as they are not so relevant.

Here are two links
The first one is some general research done on rats. I’m not sure if you guys want to use it?!!

www.reproduction-online.org/cgi/reprint/48/1/1.pdf

reducing invasive testing by using maternal serum alpha-fetoprotein testing. We could use it to compare some benefits of a non-invasive test.

http://www.nejm.org/doi/pdf/10.1056/NEJM199404213301603

--[[User:Z3254433|z3254433]] 11:28, 17 August 2010 (UTC)

Hey guys,

I think right now we have come up with the basic lay out of the site, I suggest that we split up the parts in our next lab class and if we come across anything that are specific for our assignment and think it's worthwhile to put in the site as well we can do that as we go along. These are some of the articles that I have been looking at:

MATERNAL SERUM ALPHA-FETOPROTEIN MEASUREMENT: A SCREENING TEST FOR DOWN SYNDROME -
http://storage0.nun.unsw.edu.au/cgi-bin/Data/db.cgi?db=fulltexttest&uid=default&view_records=1&url=http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=SFX&_method=citationSearch&_volkey=01406736%23323%23926&_version=1&md5=b96bddefb297298958f38399471d082b&Address=http://www.sciencedi

MATERNAL SERUM α-FETOPROTEIN—A MARKER OF FETAL APLASTIC CRISIS DURING INTRAUTERINE HUMAN PARVOVIRUS INFECTION -
http://storage0.nun.unsw.edu.au/cgi-bin/Data/db.cgi?db=fulltexttest&uid=default&view_records=1&url=http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=SFX&_method=citationSearch&_volkey=01406736%23329%23433&_version=1&md5=e7e29728e20dd0ed4956e51eb02c2128&Address=http://www.sciencedi

PRENATAL DIAGNOSIS OF SPINA BIFIDA AND ANENCEPHALY BY MATERNAL SERUM-ALPHA-FETOPROTEIN MEASUREMENT : A Controlled Study -
http://storage0.nun.unsw.edu.au/cgi-bin/Data/db.cgi?db=fulltexttest&uid=default&view_records=1&url=http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=SFX&_method=citationSearch&_volkey=01406736%23303%23765&_version=1&md5=bc4a8ecfac6aea060269fd3858638b59&Address=http://www.sciencedi

Alpha-fetoprotein Information, chemical composition, quantition, Standardization of AFP assay etc. - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3083.1978.tb03896.x/pdf

Overview - http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B83W2-4TX314K-5&_user=1975841&_coverDate=09%2F30%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000004218&_version=1&_urlVersion=0&_userid=1975841&md5=a7bfedcf9c80ddcf5994434da0c82603&searchtype=a

--[[User:Z3216889|3216889]] 10:56, 18 August 2010 (UTC)

hey guys,

i just put up a very rough and incomplete outline of the subheading that we can have for our assignment, so if you have any subheading you would like to add or edit those that i have put up please do so.

also if anyone has any relevant picture that we can use please post them up.

cheers.

--[[User:Z3254433|z3254433]] 23:55, 24 August 2010 (UTC)

hey, i just stuck up some basic background stuff on afp that is prety much just a dump of info so we can use it how we see fit :) hopefully will be able to add some other stuffs under the diff headings etc ^_^

--[[User:Z3186755|3186755]] 14:16, 25 August 2010 (UTC)

hey guys, just sending you a pictures via email that i drew but i think it might breach copyright so if you can edit it so that its not that would be great, also I'm uploading other pictures that i have drawn on our site. if you find any pictures that aren't copyright please post them up because i can't seem to find any!!!

--[[User:Z3254433|z3254433]] 05:43, 9 September 2010 (UTC)

ok I have chuck in the spina bifida and anencephaly detection in there, I would have the Down Syndrome detection up soon as well. I will help find pictures of thoses disorders as well and have them up as soon as possible. (Note to self: remember to edit the AFP in pregnancy so it doesn't overlap with the disorder section)

--[[User:Z3216889|3216889]] 13:52, 12 September 2010 (UTC)----

just upload the picture you emailed to us :) it should be fine hehe
anyway, just added extra parts :)
--[[User:Z3186755|3186755]] 16:00, 12 September 2010 (UTC)

hey guys, did 3290040 respond to any of the emails you sent? --[[User:Z3186755|3186755]] 11:56, 13 September 2010 (UTC)

hey,
i got no response,
Q) why won't these pics upload on our page???
[[File:Encephalocele_of_a_newborn.JPG|thumb]]
[[File:Down_Syndrome_Karyotype.png|thumb]]

--[[User:Z3254433|z3254433]] 11:18, 14 September 2010 (UTC)

ummm not sure? maybe try and just upload onto the main page and see if its like that i guess :S the other pictures seem to work fine on the main page
--[[User:Z3186755|3186755]] 15:50, 14 September 2010 (UTC)

so i redid all the references since no one knew how to edit them properly. However, i couldnt really find the proper references for the following:

Green 1995. See n. 6, p. 232

Iles and Gath 1993. See n. 30, p. 411

so i'll leave it here in discussion to be cleared up and take it off the main page hehe

--[[User:Z3186755|3186755]] 13:51, 15 September 2010 (UTC)

User:Z3305561

2010-09-15T23:35:38Z

Z3305561:

User:Z3305561

2010-09-15T23:35:11Z

Z3305561:

User:Z3305561

2010-09-15T23:16:59Z

Z3305561:

Talk:2010 Group Project 1

2010-09-15T16:41:18Z

Z3305561:

sam .. so how's it .. now i am verrrrrrrrry worried .. ??? please reply la .. is everything ok ? or ?? thanks .. anyways la .. am goin to bed ... if u want anything just call la .. :) .. cya tomz .. bye --[[User:Z3305561|Navneet Ahuja]] 16:25, 15 September 2010 (UTC)

Omg .. i just saw .. as soon as i click done .. i saw this .. omg i am so sorry .. u had to do them all alone .. i feel super bad la .. and is my part to less ?? u want me to do anything else?? and urs look so lovely with tables and all lol :)--[[User:Z3305561|Navneet Ahuja]] 16:15, 15 September 2010 (UTC)

No worries. I'll do a quick grammar check, but it all looks fine. I've worked with what I have to put together the bulk of what Alix was supposed to be doing. I hope it's okay. --[[User:Z3252833|z3252833]] 16:14, 15 September 2010 (UTC)

sorry la .. i think its ok now .. i tried .. i was like .. so stressed when no button seemed to work .. but luckily everything is fine now and yes .. thats the best i can do la .. as usual .. please feel free to change to add or do anything la .. thank u so much .. will cya tomz. :) --[[User:Z3305561|Navneet Ahuja]] 16:09, 15 September 2010 (UTC)

Hey sam .. I edited everything but i don't know why i could not save .. everytime i press save the error message pops up .. i did put in the PUBMED Id and edited the reference but it just keep showing me the error message even after the log off and log in again .. I cant understand it .. can i send the pubmed id to your email ?? i already edited everything ... omg .. I will send the whole section to your email . .can you please try to copy and paste it tomorrow morning ?? thank u .. :) --[[User:Z3305561|Navneet Ahuja]] 14:56, 15 September 2010 (UTC)

Hey i am gonna put a very non-finished version for u to see first so that u feel better lol .. i am doing the refs .. the everything now .. but just for you to see where this is goin .. i will put it up now .. and if the content is too less .. please tell me now lol ..but i think thats pretty much how much i can come up with .. i will try to do the history more tonight .. :) !! cya --[[User:Z3305561|Navneet Ahuja]] 13:31, 15 September 2010 (UTC)

Hi! Oh good, I'm sorry. I was just panicking a little. For an example about the history, look here: [http://php.med.unsw.edu.au/cellbiology/index.php?title=Group_5_Project_-_Electron_Microsopy link]. This is pretty intense, but it shows both what happened that year and why it's relevant. It also shows the referencing and how to code it. I know it's going to be hard; again, I've got family in hospital and assignments and exams too, but we have no choice here. We have to find time. Anyway, talk tomorrow. --[[User:Z3252833|z3252833]] 13:18, 15 September 2010 (UTC)

Hey there ... of course i am doing the current research thing la .. i am just a little worried about the ref lol .. and thank u for fixing everything up .. its much readable now .. i know that the history needs to be related to ultrasound but then it wouldnt be a time line ... But yeah we have to do alix part ?? now thats gonna be very difficult because i have 2 assignments coming up omg .. i am getting very worried !! anywayz i wil ltalk to you tomorrow as well and i think i will be done in about an hour or so but yes .. if u need anything just call me la .. thanks .. bye --[[User:Z3305561|Navneet Ahuja]] 13:06, 15 September 2010 (UTC)

Hey Nany. I'm going to just go and fix a few grammar things in your intro and timeline, if that's okay. Other than that, good... though wee need to explain why those historical points are relevant for ultrasound. I'll talk to you tomorrow, at any rate. Also, I finally managed to get through to Alix and she apparently has dropped the course, so we have to do her bit too. It's horribly late notice, I know, but we have to make the best of it. I'll see what I can do before tomorrow, but it's going to be hard. I looked at the page and you haven't put anything up but the history yet. I really, really hope you are doing the current research bit right now because I know we're both busy but I've managed to do an awful lot for my part, and with Alix gone we don't have much, and this is not a good standard. Sorry to sound so grim, but we're not in a good place. I'm counting on you. See you tomorrow. --[[User:Z3252833|z3252833]] 12:12, 15 September 2010 (UTC)

Hey sam .. I have already added a little intro ... and Its not an actual publication or an article its from a website .. so how do i reference that ?? and the website is [http://www.ob-ultrasound.net/history1.html History] this one .. errm ?? sorry la .. :)--[[User:Z3305561|Navneet Ahuja]] 11:21, 15 September 2010 (UTC)

As I mentioned today, the timeline is great. I think an intro to it/overview would also be great, and references should be added in ASAP. Alix, we still haven't heard from you... are you okay? I'm a little concerned now. Are you still doing the course? Please, get back to me when you can! --[[User:Z3252833|z3252833]] 07:23, 15 September 2010 (UTC)

Hey guys ,.. i have uploaded the time line a couple of days back .. i dont know if its ok or not la .. so if u think something is wrong please tell me or feel free to change or edit anything la .. :) thank u ... --[[User:Z3305561|Navneet Ahuja]] 07:17, 15 September 2010 (UTC) nany

Hey guys! So I've gotten permission to use some ultrasound images and have uploaded them to the site. I'm still arguing with the scanner, but I will definitely have those drawn diagrams up by Sunday afternoon, even if I have to take photos of them and upload them that way (it would be sooner, but with my Grandmother in hospital and work I have some time issues). I have four images left to upload: a drawing of an ultrasound scan line, and the three transducers and ultrasound scan patterns. I'm glad you liked the table Nany, I hoped it would make things simple. How are you going with your timeline?

Alix, are you okay? We haven't heard from you in a while, and this is due for peer assessment on Thursday. I know we agreed that due to time constrictions on all our parts we would do the majority of out putting-information-up this week - are you going okay with your part?--[[User:Z3252833|Samantha Guinn]] 09:25, 10 September 2010 (UTC)

Hey there ...Sam i read through ur part and loved the table .. made things clear but i didnt get a chance to read through all the details yet and dont worry about my part it will be up very soon .. Tomorrow morning is my flight so the next time i can come online is friday morning (when i reach sydney) and i hope everything will be up by friday night if i am not too jetlagged lol .. anywayz .. I just wanted to update la .. :) --[[User:Z3305561|Navneet Ahuja]] 18:14, 8 September 2010 (UTC) Nany

Hi again! Hope you're all having a lovely break. I've put up a revised version of my section, and added some extra stuff. I've drawn the diagrams we need freehand since I find it easier than digitally, and am in the process of scanning them. They'll be up soon. Also, I'm in negotiations over some images for us to use. If you guys could have a read through of it and let me know what you think, that'd be awesome. Thanks! --[[User:Z3252833|z3252833]] 01:59, 6 September 2010 (UTC)

Hey guys..I read your part sam and i loved the glossary ...and u mentioned u sent emails .. I didnt get any la .. I am sorry but is it to Nany_van@hotmail.com because i really did not get anything..and yes for my part i will put it up soon may be this weekend (is that too late??? lol) and what did i miss from today's lab ? did mark mention anything about the gorup work ? are we goin ok ? thanks guy cya soon nany --[[User:Z3305561|Navneet Ahuja]] 01:33, 2 September 2010 (UTC)

Hey guys! I've put up part of my draft so that we have something up on the page. I know it's heavy on text but hopefully I'm going to cut that down a little, when I put the diagrams up and it becomes clearer. I'm in the process of making some diagrams for the kinds of scans, and I've emailed some people about ultrasound pictures, but they've not gotten back to me yet (so all those '(DIAGRAM)' bits will be replaced with actual pictures soon!). Worst comes to worst and I can't find a source of good ultrasound pictures in the public domain other than Wiki Commons, I'll draw more diagrams myself. Also, I haven't put up my stuff about Doppler or 3D ultrasound or the comparison of the types yet; they're coming - I have the info, I'm just trying to make it as clear and concise as possible. In other words, I'm getting there. I'll sort out the references soon too; I have another paper or two of interest but I'm having trouble downloading the whole things rather than just the abstracts. It's a computer thing and I'll sort it out soon. Also, I've shoved some terms into the glossary - tell me if they make sense. Hope you're going well! --[[User:Z3252833|z3252833]] 23:15, 1 September 2010 (UTC)

Dear mark .. I have already sent you an email regarding my leave on the next lab.. And as i've previously mentioned to my team mates i will still contribute to the group work but i just wanted to inform them that the reply might not be as instant as when i am here because of time differences and clashes on schedule ..--[[User:Z3305561|Navneet Ahuja]] 11:51, 31 August 2010 (UTC)

--[[User:S8600021|Mark Hill]] 00:42, 31 August 2010 (UTC) Z3305561 You should contact me if you will be absent from laboratories. Also there is no reason that you cannot still contribute to group work as long as you have internet access. It is important that you complete your contributions before the peer assessment in the first week after the mid-semester break.

===Importantly there is currently no content on your project page.===

Hey guys i have to tell u something .. i will not be here for the next lab because i have to fly back to thailand for some issue thing .. Actually my flight was initially booked on thursday but now i have to go on wednesday so i wont be here for this week's lab .. I am soooo suppper sorry but of course we can still chat and talk and u know exchange infromation .. and u will definetly hear from me even when i am in thailand .. I have internet la lol .. my email is nany_van@hotmail.com so i think that might be a faster way to contact me .. I have already started on my part and will put the content asap .. (may be a couple of days..) and u guys can change or do what ever u guys want la .. I know it would be a little harder since i am in thailand to have instant reply but feel free to add , delete anything la .. and yes I will say this again .. I am deeply sorry i will have to miss the lab but if theres anything i can do pleasssssse let me know la and if i am behind in the project please let me know too la !!! ... cya guys soon :) !! well that is after the midsem

p.s. anyone wants anything from thailand ?? lol !!! nany---[[User:Z3305561|Navneet Ahuja]] 09:19, 30 August 2010 (UTC)

Hey alix ... get well soon la .. and don't worry about the lab ..!!! I am trying to search the "relevant resources" too .. like .. I was up the whole week and couldnt do much .. sorry about that guys .. anyways .. cya soon :) nany---[[User:Z3305561|Navneet Ahuja]] 23:23, 25 August 2010 (UTC)

I hope you feel better soon! I've been searching for public domain images; I'm finding them hard to come by. Here, however, is a link to a number of public domain images available on Wikipedia commons; they're not stunning but may be helpful: [http://commons.wikimedia.org/w/index.php?title=Special%3ASearch&search=ultrasound Potential ultrasound public domain images] And here is another site I've found to be useful in explaining the basics of ultrasound : [http://www.ob-ultrasound.net/ Obstetric Ultrasound: A comprehensive guide]--[[User:Z3252833|z3252833]] 23:00, 25 August 2010 (UTC)

Hi, I am also sorry but I am sorry because Im not going to be there this morning as I'm not too well. However if you need me I will be next to my computer for the duration of the lab and can be contacted via this discussion board. Sorry again.

--[[User:Z3288088|z3288088]] 21:30, 25 August 2010 (UTC)

Hey guys .. I am sorry i haven't done much either .. and i am so sorry to hear that ur grandmother fell down .. Don't worry about it and i think our first deadline is due not next week but after the midsemester break ...!!! and i am gathering information for my part too .. its not structured yet .. will do it during this weekend too .. :) nany--[[User:Z3305561|Navneet Ahuja]] 11:40, 25 August 2010 (UTC)

Hi guys. I'm sorry I haven't written anything on the page this week. I had planned to have a draft yesterday, after my anatomy exam was done, but my grandmother had a fall yesterday afternoon and is now in hospital and can barely walk, so I'm afraid I didn't get to putting up my draft, and probably won't have anything up until the weekend. I know our first deadline is next week; I definitely have time on the weekend to get things done, and will have my draft up ASAP. Sorry, again! I'm doing what I can right now. I am designing a drawing for our page to explain the workings of ultrasound; it will be up be next week too. Also, in regards to Mark Hill's comment that we have no reference material, I have previously stated that I am currently using old-school information - hard copies of books - as reference, and they can't be linked to on this page (though I did give a link to on of the books I'm using). I'll tell you guys what I know when I see you, and you'll see the information when I have the draft up, but unitl then, there's not much I can do. See you tomorrow!--[[User:Z3252833|z3252833]] 10:06, 25 August 2010 (UTC)

--[[User:S8600021|Mark Hill]] 04:32, 23 August 2010 (UTC) I cannot see any reference material here, other than the infection ref, or related images.

So as discussed
We are each working on the following;

Nany;

• History

• Current Research and Future Directions

Samantha;

• Science

• Risks and Regulations

Alix;

• Uses

• Advantages vs. Disadvantages

--[[User:Z3288088|z3288088]] 00:51, 19 August 2010 (UTC)

Hello again! No problems, Nany. Nice start with the history; I think it's going to be easier to talk tomorrow than to write it here. It's hard to show what I've got since at the moment I'm mostly using a completely non-digital (and thus non-linkable) resource; a book called Diagnostic Ultrasound: Principles and Intstruments. Thihttp://php.med.unsw.edu.au/embryology/index.php?title=Talk:2010_Group_Project_1&action=edits is it, but you can't preview it online:

[http://books.google.com.au/books?id=kK2PQgAACAAJ&dq=diagnostic+ultrasound+principles+and+instruments&hl=en&ei=htBrTMaNFNO6ce6t8Fo&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDEQ6AEwAA]

Also, this site by Discovery Health gives a simple overview of the workings of Ultrasound: [http://health.howstuffworks.com/medicine/tests-treatment/ultrasound2.htm Discovery Health Ultrasound]

See you tomorrow!--[[User:Z3252833|z3252833]] 12:30, 18 August 2010 (UTC)

Hey guys...sorry for the last minute thing la ... its been a really hectic week and yes i do totally agree with the "table" idea since if it was me i would want all important points summarised as well ... and the time line for the history part is a must but since there is soooo much info for the history .. we gotta select out the most important once i guess.. !!! Ok here we go ...History of ultrasound...

In order to know how ultrasound works we first need to understand how sound waves work..i found not an article but a full website based on how it was developed .. errm .. it gives us an "IN DEPT" detail from 1826 .. Like i think we really select the information ...

1974= As for high frequency 'ultrasound', Lazzaro Spallanzani, an Italian biologist, could be credited for it's discovery

1826 = Jean-Daniel Colladon, a Swiss physicist, had successfully used an underwater bell to determine the speed of sound in the waters

1880 = The real breakthrough in the evolution of high frequency echo-sounding techniques was discovered by Pierre Curie and his brother Jacques Curie

1914 = The first working sonar system was designed and built in the United States by Canadian Reginald Fessenden

(this is just an example of the first couple of paragraph ...!! lol )

[http://www.ob-ultrasound.net/ultrasonics_history.html History summaried]

[http://www.ob-ultrasound.net/history1.html Full History] --[[User:Z3305561|Navneet Ahuja]] 11:21, 18 August 2010 (UTC)

No worries! :)

What you've outlined sounds fantastic to me (and kudos for being so organised). Awesome! Honestly, I think our main problem is just going to be keeping it concise, since we need to keep a focus on diagnosing abnormalities too. Do you think a table would be a good way to present it? Just 'cause this is supposed to be aimed at our peers, and I know heaps of text makes me zone out but tables seem to make information easier to digest. Just a thought...

And - also just a thought - maybe we could do a timeline diagram of the history, too, to make it easier to read? It's also another way we can make our own diagram, which means we don't have to tackle all those copyright issues and we fulfill assessment criteria. I'm trying to put the "How it works" into a table or a flowchart, though I'm still researching it as well.

Is everyone doing alright with their bits so far? :) --[[User:Z3252833|z3252833]] 23:47, 16 August 2010 (UTC)

Oops, well I was just following Nany :P

So ultrasounds are done differently at different stages of the pregnancy, in the first, second and third trimester and they can also be used in the delivery process. Therefore I think the use and techniques of ultrasound would be best divided up into those 4 categories;

1. First Trimester

Ultrasounds preformed vaginally

2. Second Trimester

Ultrasounds preformed on maternal abdomen

3. Third Trimester

Also preformed on mummy’s tummy

4. Delivery

To guide the inducing of a foetus or to determine if a caesarean is necessary

[http://www.ncbi.nlm.nih.gov/pubmed/20173318 Ultrasound in Labour and Delivery]

The routine ultrasound done for most women at 18-20 weeks generally looks for the following things;

• Foetal growth

• Foetal age/Delivery date

• Heartbeat

• Placental positioning

• Identify possible congenital abnormalities

• Detect ectopic pregnancies

• Check for multiple pregnancy

• Determine sex (just out of interest to parents, not medically necessary)

The below articles looks at some of the above characteristics and how they are used;

[http://www.ncbi.nlm.nih.gov/pubmed/11930060 US evaluation of foetal growth: prediction of neonatal outcomes.]

[http://www.ncbi.nlm.nih.gov/pubmed/18538160 First- vs second-trimester ultrasound: the effect on pregnancy dating and perinatal outcomes.]

[http://www.ncbi.nlm.nih.gov/pubmed/11331644 Transvaginal sonographic assessment of cervical length changes during triplet gestation.]

Also used to guide other diagnostic procedures such as chronic villus sampling and amniocentesis.

That’s mostly normal uses at the moment, will look at their use in diagnosis of abnormalities later

--[[User:Z3288088|z3288088]] 01:57, 12 August 2010 (UTC)

Hey again guys! (I think we're supposed to post at the top of the page instead of the bottom, so that's what I'm doing, if you're wondering.) So in terms of links to search Pubmed I made these last week on my student page so I'll paste them here. And I also have the Wiki code here for making the reference list and referencing Pubmed articles, for future reference.

Search Bookshelf: [http://www.ncbi.nlm.nih.gov/sites/entrez?db=Books&cmd=search&term=Ultrasound Ultrasound]

Search Pubmed: [http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=Ultrasound Ultrasound]

Ultrasound and the risk of nosocomial cross infection <ref><pubmed>20681005</pubmed></ref>

'''Reference'''

<references/>
--[[User:Z3252833|z3252833]] 01:32, 12 August 2010 (UTC)

Hi group! So we should probably decide how much of the incredible amount of information on ultrasounds we're going to cover. I'm going to suggest - and feel free to disagree/agree/comment/whatever - that we do a least a bit on the sicence of how ultrasounds actually work before going into how you can use them to diagnose conditions prenatally. We're supposed to have at least one student-drawn diagram on our page and I figure we could have a diagram explaining how an ultrasound works, which would cover that objective. If you guys think it's an okay idea, I'd like to offer to cover this point - I love finding out how things work.

Also, if you have the time, could we just quickly email each other (even just a blank email) so we know the addresses work and no-one has a wrong spelling or anything? And whilst you guys have my email, I failed to be organised and don't have yours, so if it's not too much trouble to drop me a line... Thanks! :) --[[User:Z3252833|z3252833]] 01:18, 9 August 2010 (UTC)

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hey there ... ermm i totally think the knowing how it works before jumping to prenatal diagnosis would be a great idea...and I am totally cool if you want the hand drawn image to be on how ultrasound works ... but wont that be complicated ? isnt drawing prenatal ultrasound be easier (like a pregnant women and the machine on her stomach) - if that made anysense lol .. and yes i would send u both email immidiatly ... (nany) :) --[[User:Z3305561|Navneet Ahuja]] 09:05, 9 August 2010 (UTC)

The science idea sounds good, and I agree with Sam it would be a good one for a diagram. I also think a historical overview of the development and use of ultrasound might be good. Then what its used for in terms of diagnosis (obviously necessary) and perhaps also a section on the risks, though they are few they do exist and there are reports/studies on them. I think this would be interesting... Anyway I will see you in 20minutes-ish so we can discuss it. --[[User:Z3288088|z3288088]] 22:42, 11 August 2010 (UTC)
PS. forgot to email you, will do soon :)

2010-09-15T15:02:50Z

Z3305561: /* Current Research and Future Uses in Prenatal Diagnosis */

=Ultrasound=

==Introduction==

Today, ultrasound is known to almost everyone in the developed world as the "normal" prenatal examination that pregnant women undergo to assess the development of their pregnancy. Ultrasound scans reveal the size and position of the fetus, its sex, approximate gestational age, the number of fetuses, and generally useful information to chart the progress of the growing fetus. Ultrasound can also be of great help in the prenatal diagnosis of structural abnormalities, revealing before birth physical developmental defects such as cleft lip or abnormal limb growth and allowing parents and physicians to prepare for these situations and make early decisions about important issues such as termination and treatment.

==History Time Line==

Interest and research into ultrasound began as early as the 1700’s and had been continuously developing until now. It had transformed from a simple piece of machinery which was mainly used for navigation in World war I and a powerful locator for ships and seafaring vessels to a more complex machine in more modern times which is now used as a main prenatal diagnostic tool. Generating heat for patient therapy was initially the main use of ultrasound in the medical field, but it was later developed into a therapeutic tool (e.g. using vibrations to stimulate regrowth of bone in immobilised fractures) and more recently has become important in prenatal diagnosis, as well as in the diagnosis of diseases and injuries. <ref name="website">Woo, Joseph (2002) A short history of the development of ultrasound in obstetrics and gynecology. Accessed 13/9/2010<http://www.ob-ultrasound.net/history1.html></ref>

The following time-line briefly highlights some of the important discoveries in relation to ultrasound.

*'''1794'''- Lazzaro Spallanzani proposed that bats use hearing rather than sight to move with the aid of "high-frequency ultrasound"

*'''1880'''- Pierre Curie and Jacques Curie asserted the piezoelectric effect which lead to the creation of the transducer

*'''1826'''-Jean Daniel Colladon successfully measured the speed of sound underwater

*'''1914'''-Reginald Fessenden created the first operating sonar system to detect ice bergs underwater

*'''1920'''-Paul Langévin used ultrasound for clinical therapy

*'''1938'''- Raimar Pohlman demonstrated the therapeutic uses of ultrasound by creating ultrasonic physiotherapy

*'''1942'''- Lynn and Putnam destroyed brain cells using ultrasound waves

*'''1963'''- Donald and MacVicar detected the gestational sac of the embryo using ultrasound

*'''1972''' -Hugh Robinson used ultrasound to detect fetal heart beats and crown-to-rump length

*'''1973'''- George Radovanovitch and David Carpenter created grey-scale images of prenatal embryos

*'''1965'''- Walter Krause and Richard Soldner created real time scanner which can capture 15 images per second

*'''1984'''- Kazunori Baba first invented 3-D ultrasound

*'''1996'''- Nelson researches on 4-D (motion 3-D) fetal echocardiography<ref name="website"></ref>

Link for more history | [http://www.ob-ultrasound.net/history1.html History of Ultrasound]

==How It Works==

The basic principle of ultrasound is similar to that of sonar – that is, sending out pulses of high-frequency sound waves, receiving back the echoes of those waves after they bounce off surrounding materials, and constructing a picture of those materials from the received sounds. In medical ultrasound, or sonography, pulses of ultrasound are repeatedly sent into the body where they bounce off the edges of organs and tissues, relaying that anatomical information back to the ultrasound machine. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp3-5</ref>

'''There are three main elements in an ultrasound system: the transducer, the machine and the recording devices''' <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 28-31</ref>.

====The Transducer====

The transducer is the piece of equipment in contact with the patient. It emits the ultrasound pulses and receives the echoes of those pulses. Information about the patient’s tissues is generated by calculating the time it takes for the ultrasound pulses to scatter and bounce off those tissues and travel back to the transducer. The ultrasound waves will take longer or shorter amounts of time to travel through different tissues depending on their properties.

Since air diminishes the integrity of the ultrasound signals (the ultrasound can bounce off even a thin layer of air, almost completely preventing the penetration of the ultrasound into the patient’s tissues), a medium such as a water-soluble gel is applied between the transducer and the patient’s skin to improve the interface between the two. There are several kinds of transducers producing different kinds of ultrasound images, discussed below. Transducers can be non-invasive (for prenatal diagnosis, pressed against the woman's pelvis or abdomen) or they can be invasive (transvaginal transducers, for example, are inserted into the vagina to obtain better views of the ovaries, fallopian tubes, uterus, and surrounding structures).

[[File:ZScan_Lines.jpg|thumb|right|Diagram showing a single scan line on the left and an image comprised of many scan lines on the right]]
Within the transducer are elements made of silicon crystals. The pulses of ultrasound are created using the piezoelectric effect – when silicon crystals experience electrical impulses they mechanically deform on a microscopic level, producing high-frequency sound waves. Returning sound waves (echoes) will similarly deform the silicon crystals, and these deformations are converted to electrical impulses which are then sent to the ultrasound machine for processing. Different kinds of transducers will produce different kinds of images, or scans. High-frequency transducers (5MHz or greater) give better resolution of images, but low frequency transducers penetrate deeper into tissues and so provide images of deeper structures. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 28-31</ref>

Sending one ultrasound pulse into the body will generate a line of dots – this represents one line of echo information, or one scan line. Not all of that pulse bounces back off one single anatomical structure; instead, most of the pulse continues through to deeper structures where some of the pulse bounces back from each structure it passes through. This is what generates the line of dots representing an internal view of the patient. Since the echoes of a single pulse generate one scan line of information, generating several scan lines next to one another in an ordered sequence will generate a cross-sectional image of the patient (see the diagram on the right). This way of directing pulses through the tissues is termed “scanning” or “sweeping”. Scanning is performed quickly and automatically by an “array” of organised group of transducer elements, creating many still images or frames which are viewed in sequence, like a movie. Thus, ultrasound exams are performed in real-time. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp3-9</ref>

Different transducers have different arrays of piezoelectric elements, and produce a variety of different scans or images:

{| border="1" cellpadding="5" cellspacing="0" align="center"
|+ '''Types of Transducers and Scans'''
|-
! style="background: yellow; color: black" | Linear Array Transducers
! style="background: green; color: white" | Curved or Convex Array Transducers
! style="background: blue; color: white" | Phased Array Transducers
|-
| Elements are arranged in a straight line, firing pulses vertically and parallel to each other
| Elements are arranged nest to each other in a convex shape, emitting pulses in a sunburst-like manner
| Emit pulses from a compact line of elements in slightly different directions in rapid sequence
|-
| The kind of image formed is called a linear or rectangular scan
| The kind of image formed is a sector or modified sector scan
| The kind of image formed is a sector scan
|-
| align="center" width="150" | [[File:ZLinear_Array_Transducer.jpg|200px]]
| align="center" width="150" | [[File:ZConvex_Array_Transducer.jpg|350px]]
| align="center" width="150" | [[File:ZPhased_Array_Transducerki.jpg|200px]]
|}

====The Ultrasound Machine and Recording Devices====
[[File:ZUltrasound_Image_of_Fetal_Aorta.jpg|thumb|right|2D ultrasound image of a sagittal section of a fetal chest, showing the typical greyscale appearance of ultrasound images]]

The ultrasound machine itself is comprised of the computer hardware and software needed to convert the signals picked up by the transducer into an image that can be viewed. The image is in greyscale, using various shades from black to white to indicate different tissues and tissue features.

The other basic part of the ultrasound system is the recording equipment – that is, a range of devices such as multiformat cameras, video printers and video recorders used to store information from the patient’s examination.

So far, what has been explained are the basic principles of how a normal 2D ultrasound image is generated. There have been are, however, some developments in ultrasound technology that allow the generation of slightly different images to the normal 2D ones, providing more diagnostic information. These are the Doppler ultrasound and 3D ultrasound imaging.

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

===Doppler Ultrasound===
[[File:ZDoppler_Image_of_Fetal_Aorta.jpg|thumb|left|Colour Doppler ultrasound image showing a saggital section of the aortic arch and descending aorta of the fetus]]

Doppler ultrasound utilises the Doppler effect to view moving structures, such as the flow of blood through major blood vessels of the heart. The Doppler effect refers to the change in frequency of a wave relative to the motion of the wave source and the observer. In a Doppler ultrasound, sound waved are reflected from moving structures with a shift in frequency of those sound waves proportional to the velocity of the moving structure.<ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 30</ref>

Continuous-wave Doppler ultrasound detects signals from anything moving in the path of the pulse, and cannot distinguish well between separate vessels. Pulsed Doppler ultrasound uses a pulse in a thin, focused beam and detects signals from only one point in that beam, allowing the imaging of specific vessels. Colour Doppler imaging is a type of pulsed Doppler ultrasound where software is used to overlay the greyscale image with colours representing frequency shifts. Different colours are assigned to indicate movement towards or away from the transducer. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp 185-186</ref><ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 30</ref>

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

Link to video of the Doppler Effect | [http://videos.howstuffworks.com/discovery/27963-assignment-discovery-doppler-effect-video.htm Assignment Discovery: the Doppler Effect]

===3D Ultrasound===
[[File:Z3DCleft_Lip_Picture.jpg|thumb|right|3D ultrasound image showing a fetus with a cleft lip abnormality]]

Three-dimensional ultrasound images are produced in one of several ways. The first is to have several arrays of 2D transducers working together to collect a series of 2D cross-sections and combine these into a 3D image, though this can be difficult. 3D ultrasound images can also be made with the use of arrays of 1D transducers to create 2D B-scan images of known areas in 3D space. The 1D arrays can either by swept across the patient by machine or by the technician. 3D ultrasound images are particularly useful for visualising the volumes of structures, and better viewing complex 3D structures. However, even today it is mostly 2D ultrasound that is used, with 3D ultrasound only used in select applications. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp. 6</ref><ref><pubmed>20349815</pubmed></ref>

Link to more ultrasound images | [http://www.ultrasound-images.com/ Ultrasound Images]

Link to a review of 3D ultrasound imaging | [http://www.ncbi.nlm.nih.gov/pubmed/20349815 Three-dimensional ultrasound imaging]

==Current Uses in Prenatal Diagnosis==

Subheadings: Normal uses during pregnancy/Diagnosing abnormalities?

==Risks and Regulations==

Epidemiological studies have not indicated any identifiable risks associated with the use of ultrasound as a diagnostic tool. Animal studies have indicated that only at intensities higher than expected in pertinent tissues during ultrasound imaging are any bioeffects evident. The World Health Organization has given the statement that, “the benefits of this imaging modality far outweigh any presumed risks”<ref>World Health Organization: ‘’Environmental health criteria 22: ultrasound’’, Geneva, 1982, The Organization.</ref><ref>World Health Organization: Ultrasound. In Nonionizing radiation protection, ed 2, Geneva, 1989, The Organization.</ref> As there is currently no known risk but there are known benefits of the procedure, it is considered safe, but a conservative approach should still be taken to ensure that ultrasound exams are not given unnecessarily or excessively. <ref>Kremkali, F.W. (2006) Diagnostic Ultrasound Principles and Instruments (7th ed.) St Louis: Saunders Elsevier. pp332-333</ref>

There is however a risk of misdiagnosis by the ultrasound technician, which could cause undue parental anxiety. This can, for the most part, be avoided by ensuring ultrasound operators are all sufficiently trained and experienced. <ref>Ellwood, D.A. (1995) The Role of Ultrasound in Prenatal Diagnosis. In Trent, R.J. (Ed.), Handbook of Prenatal Diagnosis. Cambridge, England: Cambridge University Press, pp. 29</ref>

==Current Research and Future Uses in Prenatal Diagnosis==

Ultrasound is currently being used in various fields for multi purposes such as diagnosing major fetus diseases. It is also used to see the placental location and “vascular system”. Moreover recent discoveries also made the mother-fetus interaction visualizable by being able to see the development of placenta and the changes in blood vessels during pregnancy <ref><pubmed>20034427</pubmed></ref>.

Another example of current research would be using ultrasound to detect the early FASD (fetal alcohol spectrum disorder) symptoms on alcoholic mothers by examining the abnormal facial features of the fetus for better prevention and treatment since it was known to have many birth defects such as impared growth or cognitive dysfunction<ref><pubmed>19444822</pubmed></ref>. Although heart beat is considered normal to be seen in ultrasound but lately a droppler ultrasound that could detect breathing movement of the fetus was also made availabe.

In addition, There was also a media report that 3-D ultrasound shows “complex behaviors” which would be considered impossible for an unborn such as yawning and sucking in the womb.[http://news.bbc.co.uk/2/hi/health/3846525.stm BBC news] It was considered a powerful tool to study behaviours in an infant. Ultrasound is also used to detect adverse pregnancy outcome as early as 11-13 weeks to avoid complications to both mother and fetus.

Further uses, a lot of researches are aiming to develop a better resolution a more interactive ultrasound machine for better diagnosis and treatment. It was also thought to be the next

==Links for Further Reading==

==Glossary==

'''B-scan:''' A way to map the body or an area of the body using a sensing device

'''Bioeffects:''' Adverse biological effects

'''Linear image:''' A rectangular image produced by a transducer with elements next to each other, giving off ultrasound pulses in parallel lines

'''Modified sector scan:''' A fan-shaped image with a curved top produced by a transducer with elements next to each other that also emit pulses in different directions

'''Piezoelectric effect:''' When silicon crystals experience electrical impulses they mechanically deform on a microscopic level, producing high-frequency sound waves

'''Pulse-echo technique:''' A technique in ultrasound where short pulses of ultrasound are emitted into the area to be studied, and echoes are received and interpreted to give information about the internal anatomical structures by calculating the time taken for the ultrasound echoes to return to the transducer

'''Scan line:''' The line of dots representing the information from one pulse of ultrasound

'''Sonographer:''' A trained ultrasound technician

'''Sonography:''' Medical anatomical imaging using ultrasound

'''Sonologist:''' A medical practitioner who is a trained ultrasound technician

'''Sector scan:''' A fan-shaped image produced by a transducer with ultrasound pulses emitting from the same point but in different directions

'''Transducer:''' The part of the ultrasound apparatus that is in contact with the patient; it emits the pulses and receives the echoes of ultrasound

==References==

<references/>

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