Ultrasound will travel through blood in the heart chamber, for example, but if it hits a heart valve, it will echo, or bounce back. It will travel straight through the gallbladder if there are no gallstones , but if there are stones, it will bounce back from them. This bouncing back, or echo, gives the ultrasound image its features. Varying shades of gray reflect different densities.
Some very small transducers can be placed onto the end of a catheter and inserted into blood vessels to examine the walls of blood vessels. Ultrasound is commonly used for diagnosis, for treatment, and for guidance during procedures such as biopsies.
It can be used to examine internal organs such as the liver and kidneys, the pancreas, the thyroid gland, the testes and the ovaries, and others. An ultrasound scan can reveal whether a lump is a tumor. This could be cancerous, or a fluid-filled cyst. It can help diagnose problems with soft tissues, muscles, blood vessels, tendons, and joints. It is used to investigate a frozen shoulder , tennis elbow , carpal tunnel syndrome , and others.
Doppler ultrasound can assess the flow of blood in a vessel or blood pressure. It can determine the speed of the blood flow and any obstructions. An echocardiogram ECG is an example of Doppler ultrasound. It can be used to create images of the cardiovascular system and to measure blood flow and cardiac tissue movement at specific points.
A Doppler ultrasound can assess the function and state of cardiac valve areas, any abnormalities in the heart, valvular regurgitation, or blood leaking from valves, and it can show how well the heart pumps out blood. A carotid duplex is a form of carotid ultrasonography that may include a Doppler ultrasound. This would reveal how blood cells move through the carotid arteries.
Ultrasound is often used by anesthetists to guide a needle with anesthetic solutions near nerves. Most scans take between 20 and 60 minutes. It is not normally painful, and there is no noise. In most cases, no special preparation is needed, but patients may wish to wear loose-fitting and comfortable clothing.
If the liver or gallbladder is affected, the patient may have to fast, or eat nothing, for several hours before the procedure. The computer can especially recognize fluid that is flowing toward or away from the transducer and uses color overlays on the image to show direction of flow. Very hard and dense tissues or empty spaces, such as organs filled with gas, do not conduct ultrasound waves and therefore cannot be viewed on a sonogram. Sonography is often used before moving to imaging technologies that have more potential for complications.
Magnetic resonance imaging MRI uses an extremely strong magnet to capture the image. The strength of an MRI magnet can limit its use in patients with metal in their bodies braces, for example. A sonogram is a noninvasive imaging test and has no known complications. Ultrasound waves are thought to be harmless and the test is usually performed externally on the surface of the skin. Sonography has no known risks or complications when used externally on the surface of the skin.
While the energy of the ultrasound waves could potentially irritate or disrupt tissues with prolonged exposure, the computer modulates the power of the sound and a trained technician uses techniques to minimize exposure times and angles.
So, sonography is the safest of the imaging tests. Healthcare providers order sonography often as a first-line test, usually together with blood tests.
Make sure you ask the healthcare provider if there are any special instructions before the sonogram. In an emergency setting, sonography will typically be performed right away. For a test on a future date, find out if you should, or should not, eat or drink anything before the test. For example, healthcare providers will often ask you to fast not eat or drink for six hours before an abdominal ultrasound to look at the gallbladder, but tell you to drink several glasses of water and not urinate before a sonogram of the bladder.
If the test requires that you drink fluids to have a full bladder, you might need to drink water before the test if the bladder is not full enough. This might happen after the technician tries the test first. Once the technician acquires all of the pictures, he or she will check with the radiologist healthcare provider trained to read images to make sure no other views are required. Most of the time, the technician is not able to give you any results.
Once the radiologist interprets the images from the sonogram, the report will be made available to your healthcare provider. Sonography is done at most imaging centers, hospitals, and some obstetrics offices. The sonography machine looks a bit like a computer with a microphone attached, almost like a Karaoke machine. Usually, the sonography machine is rolled right up to the bedside.
What to Wear. You should wear something easy to remove. In most cases, you will only have to expose the skin that the technician is going to need access to. An abdominal ultrasound, for example, can be done wearing pants and a shirt. You will just have to pull the shirt up to expose the abdomen. In the case of a transvaginal sonogram, you will have to undress below the waste, including removing the underwear.
Food and Drink. As noted above, the reason for the sonography will determine whether you needs to fast, drink fluids, or neither. Cost and Health Insurance. Sonography is a relatively inexpensive imaging test. It is covered by most insurances and might require pre-authorization depending on the reason the healthcare provider ordered the sonogram.
A 3D or 4D sonogram is an elective test that some parents will get during pregnancy. The 3D image shows a 3-dimensional rendering of the baby, while 4D refers to an animated video rendering of the baby in utero captured over time.
These are known as entertainment tests and are not covered by most health insurances. Here's what you can expect before, during, and after a sonogram. Plan to arrive slightly earlier than your appointment so that you can check in and fill out any necessary paperwork. If you were asked to follow specific food and drink instructions, you will be asked to confirm that you did.
Throughout the Test. A sonogram is conducted by a single technician right at the bedside. The entire sonogram will likely take less than 30 minutes. An ultrasound technician, called a sonographer, will apply a special lubricating jelly to your skin. This prevents friction so they can rub the ultrasound transducer on your skin. The transducer has a similar appearance to a microphone. The jelly also helps transmit the sound waves.
The transducer sends high-frequency sound waves through your body. The waves echo as they hit a dense object, such as an organ or bone.
Those echoes are then reflected back into a computer. The sound waves are at too high of a pitch for the human ear to hear. They form a picture that can be interpreted by the doctor. Depending on the area being examined, you may need to change positions so the technician can have better access. After the procedure, the gel will be cleaned off of your skin. The whole procedure typically lasts less than 30 minutes, depending on the area being examined.
You will be free to go about your normal activities after the procedure has finished. Following the exam, your doctor will review the images and check for any abnormalities. They will call you to discuss the findings, or to schedule a follow-up appointment. Should anything abnormal turn up on the ultrasound, you may need to undergo other diagnostic techniques, such as a CT scan, MRI, or a biopsy sample of tissue depending on the area examined.
If your doctor is able to make a diagnosis of your condition based on your ultrasound, they may begin your treatment immediately. An abdominal ultrasound uses sound waves to check a number of conditions. Learn about what ultrasounds are used for and if there are any risks. The two terms are often used interchangeably, but by definition, an ultrasound is the…. A transvaginal ultrasound, also called an endovaginal ultrasound, is a type of pelvic ultrasound used by doctors to examine female reproductive organs.
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