ultrasonography
Ultrasonography uses high-frequency sound (ultrasound) to produce images of internal organs and other tissues. A machine called a transducer converts electrical energy into sound waves, which are sent to body tissues. Sound waves jump into body structures and return to the transducer, converting the waves into electrical signals. No x-rays are used, so no radiation exposure during ultrasonography.
Ultrasonography Process
If certain parts of the abdomen are examined, people may be asked to stop eating and drinking for a few hours before the test. In female genital mutilation tests, women may be asked to drink a large amount of fluid to fill their bladder.
Usually, the examiner puts a thick gel on the skin over the test area to ensure good sound transmission. A hand-held transducer is placed on the skin and transported over the surface for testing.
To examine other organs, the examiner inserts a transducer into the body - for example, into the vagina for a better picture of the uterus and eggs or anus to represent the prostate gland.
The examiner sometimes attaches a transducer to a viewing tube called an endoscope and transmits it to the body. This procedure is called endoscopic ultrasonography. The endoscope can be passed through the throat to view the heart (transesophageal echocardiography) or through the abdomen to view the liver and other nearby organs.
After the test, most people can resume their normal activities immediately.
Use of Ultrasonography
Ultrasound images are available quickly enough to show the movement of organs and structures in the body in real time (as in a movie). For example, heartbeat can be seen, even in a baby.
Ultrasonography is best used to examine growth and external factors near the surface of the body, such as those in the thyroid, breasts, testicles, and organs, as well as other lymph nodes.
Ultrasonography is best used to describe the internal organs of the abdomen, waist, and chest. People who are trained to perform ultrasound tests are called sonographers.
Ultrasonography is commonly used for the following tests:
Cardiovascular: For example, detection of irregular heartbeat, systemic irregularities such as dysfunctional heart valves, and abnormal expansion of heart chambers or walls (cardiac ultrasonography is called echocardiography)
Blood vessels: For example, finding open and narrowed blood vessels
Gallbladder and biliary tract: For example, detection of gallstones and obstruction of bile ducts
Liver, spleen and pancreas: For example, muscle gain and other disorders
Urinary Tract: For example, separating benign cyst from solid mass (which can be cancer) of the kidneys or getting a stone-like or other obstruction of the kidneys, ureters, or bladder
Female genitals: For example, tissue and inflammation in the ovaries, fallopian tubes, or uterus
Pregnancy: For example, examining fetal growth and development and detecting abnormalities in the placenta (such as the lost placenta, called placenta previa)
Ultrasonography can be used to guide physicians when removing a sample of tissue biopsy. Ultrasonography can show the shape of the biopsy metal, as well as the location of the biopsied (mass-like) material. Therefore, doctors can see where to place the device and can direct it directly to the target area.
Ultrasonography Variations
Ultrasound details can be displayed in a number of ways:
A-mode: Like spikes on a graph (used for eye scanning)
B mode: As 2-dimensional anatomic images (used during pregnancy to test the developing fetus or to examine internal organs)
M M: As the waves are continuously displayed to indicate a moving pattern (used to check the baby's heartbeat or to check for heart valve disorders)
B-mode ultrasonography was performed extensively.
Doppler ultrasonography
Doppler ultrasonography uses changes that occur when sound waves are detected from a moving object (called the Doppler effect). In medical thought, moving objects are red blood cells. Therefore, Doppler ultrasonography can be used for testing
Whether blood flows into the bloodstream
How fast it flows
Flow in either direction
Doppler ultrasonography is used
Cardiovascular function (as part of echocardiography)
Finding blocked blood vessels, especially in the arteries, as in deep vein thrombosis, where arteries are blocked
Detection of small arteries, especially carotid arteries in the neck, that carry blood to the brain
Spectral Doppler ultrasonography
This process shows the details of blood flow as a graph. It can be used to test the volume of a blocked blood vessel.
Duplex Doppler ultrasonography
This process combines spectral and B-mode ultrasonography.
Color Doppler ultrasonography
In this experiment, the color was placed on top of the shadows-of-gray image of blood flow produced by Doppler ultrasonography. The color indicates blood circulation. Red can be used to show the flow towards the transducer, and blue can be used to indicate the outflow from the transducer. The brightness of the color indicates how fast the blood runs.
Color Doppler ultrasonography can help assess the risk of stroke because it helps physicians to identify and evaluate narrowing or obstruction of the arteries in the neck and head. The process is helpful in testing
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