Obstetric Ultrasound has became a very useful tool ever since it was introduced
in the late 1950's. The current equipments used are in "real-time",
in which continuous images of the moving fetus is captured and processed
on the monitor for display. High frequency sound waves are emitted
from the transducer that comes in contact with the maternal abdomen. Repetitive
ultrasound beams that come out of the transducer are used to scan the fetus
in slices and are reflected back onto the same transducer for processing.
Eventually the information obtained from different reflections will
come together to make the image that appears on the monitor, and this information
can be used to access the fetal heart, gestational age, size and growth in
the fetus.
|
|
| Fetus at 9 weeks |
Fetus at 12-weeks demonstrating presence of the
nasal bone |
|
|
| Shortened humerus in a fetus may be associated
with high risk for Down syndrome |
The nuchal fold could indicate a high risk for
Down syndrome if thickness is increased |