Brontekst bekijken van Ultrasound imaging

Ultrasound imaging or sonography is a technique that is used in order to examine a fetus for specific qualities, defections or position.

===Ultrasound imaging: the technical story===

During ultrasound imaging for the human ear non-audible sound waves pass through tissue. The waves are dispersed by the different densities of the tissue, then spread out and are eventually detected by a transducer or probe. The frequency and intensity of the detected waves are translated into images of different colouring, which then visualizes the shape of the examined tissue. Bone has a high density and gives a white image (meaning that a lot of echoing was possible to happen). Amniotic fluid does not reflect anything and gives a black image (due to no echoing happening at all). Especially soft tissues can be examined well with this technique.

During pregnancy ultrasound imaging can be used to examine the development of the fetus. There are three types of examination that are practised in particular:
* Early pregnancy scan or viability scan or dating scan - the determination of the phase of the pregnancy, between 10 and 11 weeks of pregnancy
* Nuchal scan between 11 and 14 weeks of pregnancy
* 20 week scan at 20 weeks of pregnancy

The early pregnancy scan help in determining the age of the pregnancy so far as well as the due date. 
The nuchal scan and the 20 week scan are optional and can be seen as screening tests for chromosomal and physical abnormalities.

Sometimes additional ultrasound scans are done when the obstetrician or gynaecologist advise the future parents to do so. This can be done for example in case of blood loss during the first trimester of the pregnancy, when doubts about the growth or position of the fetus have arisen or when previous pregnancies were problematic.

Future parents can opt to go for ultrasound scans that are merely for fun, so that they can already see their child. These non-clinical ultrasound scans can be either two or three dimensionsal.

===Practical applications of ultrasound imaging===

From about 16 weeks pregnancy an ultrasound scan can be used for the determination of the gender of an unborn child. During the 20 week scan the future parents can decide whether or not they want to know the gender.

===Ultrasound imaging: the risks===

In the past research was done in order to find out whether ultrasound imaging could damage the hearing of the unborn child. It was found that this is not the case. 

As far as knowledge goes there are no side effects or risks for mother and the unborn child related to ultrasound imaging.

===Key words===

Gender determination, echo, echoscopy, echoscopist


[[File:NL_vlag.jpg|40px]] 
Read this article in Dutch: [[Echoscopie]]

[[Categorie: pregnancy and giving birth]]
[[Categorie: parenthood]]
[[Categorie: development]]