Echography
(Ultrasonography)The principle behind echography is simple. High-energy sound waves (ultrasounds) are bounced off internal organs or tissues and make echoes that are captured by a machine. The machine then converts the echoes into pictures. This type of medical imaging is possible since some parts of the body reflect sound waves. Echography is used to visualize the contours and limits of internal structures within the body. Contrary to other imaging techniques, echography does not use X-rays and does not require the use of any contrast agent.
There are many advantages to using this technique. Besides being simple, painless and fairly quick, echography has no side effects, is inexpensive and does generally not entail any complex preparation.
You may also have heard the term Doppler echography. In addition to being able to visualize the structures inside the body, Doppler echography allows us to observe large blood vessels, the heart ventricles and blood flow.
What is the purpose of this test?
Echography is used to visualize countless soft structures, more specifically their shape, contour and movement, if they move. The vessels and structures of the heart, head, neck, brain, eyes, breasts, liver, etc. can be observed through echography. This technique is also what enables parents-to-be to see the fetus for the very first time.
Cardiac echography is used when dilating (reopening) certain blood vessels of the heart. In certain medical procedures, it is also used to perform manipulations safely, such as during a biopsy (removal of a piece of tissue).
The Doppler echography is usually performed in order to detect an obstruction, a stenosis or a clot in an artery or a vein.
Preparation
Preparation depends on the area of the body to be studied. Some echographies do not require any preparation, while others require the patient to follow very specific instructions. Here is a summary of the most common recommendations for adults, based on the location of the echography.
| Examination | Preparation |
|---|---|
| Abdominal echography and Doppler | If the exam takes place in the morning, before noon:
If the exam takes place in the afternoon:
|
| Pelvic echography |
|
| Other echographies |
|
Procedure
The patient is asked to lie down for the examination. A clear, odourless, non-allergenic gel is placed on the area that is of interest to improve the contact with the probe and make it slide easily. Depending on the type of echography, the device can be passed over a body part or through a body orifice. This device sends waves through the patient and records the echoes.The captured sound waves are then converted into an image by a computer. The results are in real time. The images are interpreted by a radiologist. At times, pressure is applied, which can make the examination somewhat unpleasant. Depending on the type of ultrasound, the examination lasts from 15 to 60 minutes.
What you should know before going for this test
When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.