The basic 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 have also 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 foetus for the very first time.
Cardiac echography is used when dilating (reopening) certain blood vessels of the heart. Physicians use echography to guide them in order to safely perform the procedure.
The Doppler echography is usually performed in order to detect un obstruction, a stenosis or a clot in an artery or a vein.
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.
The patient is asked to lie down for the examination. A clear, odourless, non-allergenic gel is placed on the area of the body that is of interest. A device is then passed over the area in question. 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. The examination usually takes 15 to 30 minutes to complete.
What to know before going for this test
Before going for a blood test, examination or other, it is always a good idea for you to have a complete list of all prescription or over the counter medications and/or natural products you may be taking. If you are unsure or have any questions, your pharmacist will be able provide you with additional information.
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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.