Overview of ultrasonography or ultrasound
Ultrasonography or ultrasound is a medical test that uses high-frequency sound waves to take live pictures from inside your body. This is also known as an ultrasound.
The technology is similar to that used by sonar and radar, which helps the military to detect planes and ships. It allows your doctor to see problems with organs, vessels, and tissues without the need for an incision.
Unlike other imaging methods, ultrasound does not use radiation. For this reason, it is a preferred method of observing the development of the fetus during pregnancy.
Why is the procedure done?
Most people associate ultrasounds with pregnancy. These scans can give the expectant mother the first sight of her unborn baby. However, there are many other uses for testing.
Your doctor may order an ultrasound if you have pain, swelling, or other symptoms that require an internal view of your organs.
Provides an ultrasound view:
- Brain (in babies)
- Blood vessels
Ultrasound can also help guide a surgeon’s movements during certain medical procedures, such as biopsies.
How to prepare for ultrasonography or ultrasound?
The steps you need to take to prepare for ultrasonography depending on the area or organ being examined.
Your doctor may tell you to fast for eight to 12 hours before the ultrasound, especially if your abdomen is being examined. Undigested food can block sound waves, making it difficult for a technician to get a clear picture.
For the gallbladder, liver, pancreas, or spleen exam, you may be instructed to eat a fat-free meal the night before the test and then fast until the procedure. However, you can continue to drink water and take your prescribed medications. For other tests, you may be asked to drink lots of water and hold your urine so your bladder is full and clearly visible. Inform your doctor of any medications, over-the-counter medications, or herbal medications you may be taking before the test.
It is important to follow your doctor’s instructions and ask yourself any questions before the procedure. Ultrasound has minimal risks. Unlike X-rays or CT scans, ultrasounds do not use radiation.
How ultrasonography is performed?
Before the test, you put on a hospital gown. You can lie on a table that will expose a part of your body for the test. An ultrasound technician called a sonographer applies a special lubricating jelly to your skin. They can run an ultrasound transducer on your skin to avoid friction. The transducer has a similar appearance to the microphone. Jelly also helps transmit sound waves.
High-frequency sound waves send through your body. The waves resonate when they touch a dense object, such as an organ or bone. Those echoes are reflected in the computer. Sound waves are louder than the pitch the human ear can hear. They form a picture that the doctor can understand. Depending on the area being examined, you may need to relocate so that technicians have better access.
After the procedure, the gel will be wiped off your skin. The entire procedure usually takes less than 30 minutes, depending on the area examined. You will have the freedom to learn about your normal activities after the procedure is complete.
After the ultrasonography
After the test, your doctor will review the images and look for abnormalities. They will call you to discuss the results or to schedule the next appointment. If there are any abnormalities on the ultrasound, you may undergo other diagnostic procedures, such as a CT scan, MRI, or tissue biopsy, depending on the area examined. If your doctor can diagnose your condition based on your ultrasound, they can begin your treatment right away.
Variations of ultrasonography
- Mode A: Graph peaks (used for eye scan)
- Mode B: As two-dimensional anatomical images (used during pregnancy to assess fetal development or to assess internal organs)
- Mode M: waves are constantly displayed to show moving structures (used to assess fetal heart rate or heart valve defects)
Doppler ultrasound uses a change in the frequency of sound waves when they are reflected off a moving object (called the Doppler effect). In medical images, the moving objects are red blood cells in the blood. Therefore, Doppler ultrasound can be used to assess.
- Does blood flow through blood vessels?
- How fast it flows
- Flow in any direction
Doppler ultrasonography is used
- To assess how well the heart is working (as part of echocardiography).
- Identification of blocked blood vessels, especially in the veins of the legs, such as deep vein thrombosis, when the veins are blocked by blood clots.
- To identify narrow arteries, especially the carotid arteries in the neck, that carry blood to the brain.
Spectral doppler ultrasonography
This procedure graphically displays blood flow information. It can be used to estimate how much is blocked in a blood vessel.
Duplex doppler ultrasonography
This approach combines spectral and B-mode ultrasound.
Color doppler ultrasonography
For this test, color superposes were applied to the gray-toned image of the bloodstream produced by Doppler ultrasound. The color indicates the direction of blood flow. Red can be used to indicate current on the transducer side and blue can be used to indicate current is away from the transducer. The brightness of the color indicates how fast the blood flows.
Color doppler ultrasound can help assess stroke risk because it can help doctors diagnose and diagnose narrowing or blocked arteries in the neck and head. This approach is useful in evaluating people with transient ischemic attacks or risk factors for stroke and atherosclerosis. Color doppler ultrasound is also used to assess blood flow to internal organs and tumors.