ultrasound
Biology
(noun)
sound frequencies above the human detectable ceiling of approximately 20,000 Hz
Physics
(noun)
Sound with a frequency greater than the upper limit of human hearing; approximately 20 kilohertz.
Examples of ultrasound in the following topics:
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Applications: Ultrasound, Sonar, and Medical Imaging
- Ultrasound is sound with a frequency higher than 20 kHz.
- The most common use of ultrasound, creating images, has industrial and medical applications.
- The use of ultrasound to create images is based on the reflection and transmission of a wave at a boundary.
- When an ultrasound wave travels inside an object that is made up of different materials (such as the human body), each time it encounters a boundary (e.g., between bone and muscle, or muscle and fat), part of the wave is reflected and part of it is transmitted.
- Ultrasound waves are sent out then reflected off the objects around the animal.
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Early Pregnancy Tests
- Ultrasound is also a common tool for determining viability.
- Diagnosis should not be made from a single ultrasound, however.
- If results from the first ultrasound scan indicate a problem, repeating the scan 7–10 days later is a reasonable practice.
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Spina Bifida
- Neural tube defects can usually be detected during pregnancy by testing the mother's blood (AFP screening) or by a detailed fetal ultrasound.
- Ultrasound screening for spina bifida is partly responsible for the decline in new cases because many pregnancies are terminated out of fear that a newborn might have a poor future quality of life.
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Prenatal Diagnostic Tests
- The primary method for sex determination is prenatal ultrasound.
- In the case of neural tube defects, a detailed ultrasound can noninvasively provide a definitive diagnosis.
- At about 6 weeks of pregnancy, early dating ultrasound scan may be offered to help confirm the gestational age of the embryo and check if a single or twin pregnancy exists, but such a scan is unable to detect common abnormalities.
- The results of the blood tests are then combined with the NT ultrasound measurements, maternal age, and gestational age of the fetus to yield a risk score for Down Syndrome, Trisomy 18, and Trisomy 13.
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Energy, Intensity, Frequency, and Amplitude
- For example, the longer deep-heat ultrasound is applied, the more energy it transfers.
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Characteristics of Sound
- Ultrasound uses sound waves with high frequencies to see things normally hard to detect, like tumors.
- Animals, like bats and dolphins, use ultrasound (echolocation) to navigate and locate things.
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Introduction to Pregnancy and Human Development
- Ultrasound is used to monitor the age and health of the fetus during pregnancy.
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Pelvic Inflammatory Disease (PID)
- Different tests can be used for diagnosis such as pelvic ultrasound and laboratory tests for STIs.
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Sound
- Those frequencies above the human range are called ultrasound.
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Yolk Sac Development
- It is a critical landmark, identifying a true gestation sac, and is reliably seen in early pregnancy through ultrasound.