Docs Tag: waves
EEG
What is an EEG?
EEG is the short way of saying electroencephalogram.  In your brain there are electrical signals being passed around. These signals are called brain waves. The EEG machine measures your brain waves and records them on the computer.  The picture looks like wavy lines on the computer screen. No matter what you are doing, whether you are running, reading or sleeping, your brain always has brain waves. The EEG measures these brain waves and shows where they are in your brain and how big the waves are.
Why do I need to have an EEG?
The most common reason people have an EEG is when someone has a seizure or epilepsy, although there may be other reasons. If you are having an EEG, the doctor wants to know what is happening in your brain, and an EEG can help. The EEG measures the brain waves in your brain; it helps the doctor to see how your brain is working and where in the brain the problem is.   This helps the doctor decide what is the best medicine or treatment for you.
What does an EEG machine look like?
An EEG is a computer that has lots of wires attached to it. The wires have a sticky end that attaches to your head.  There is a bed that is beside the EEG computer, this is where you will lie down.
What happens when I have an EEG?
A porter will come and bring you to the area where you will have the EEG. A technologist (the person who does the test) will greet you and explain what will happen.  You may be given a gown to wear, this looks like a backward housecoat, or you may already be wearing one.
The technologist will ask you to lie down on a bed. She will then take the wires that are attached to the machine and place them on your head. The technologist will use a sticky soft tape and gel to help the wires stay in place. These wires are called electrodes; they measure your brain waves.
It is important to lie very still on the bed while the test is happening. Sometimes they will ask you to try to fall asleep so that they can see what your brain does when you are resting. They may also ask you to rest with your eyes open or closed, take breaths really fast or look at a flashing light. The test can take about 45 minutes. When the test is done, the technologist will remove the wires from your head and wipe off the sticky gel.
What will the EEG test feel like?
An electroencephalogram does not hurt. The gel might feel a little cold. The tape is a special gentle tape that is less sticky than a regular Band-Aid.  While the test is going on you will be able to see your brain waves on the computer screen.
Preparing for the test
Your nurse will give you the information you need to help you get ready to have your EEG.
Remember
If you have any questions about the test, always ask!
Ultrasound
What is an Ultrasound?
An ultrasound is another way doctors are able to take a look inside your body. Invisible sound waves are bounced off the places in your body your doctor needs to check out. You will not feel or hear these sound waves. They show a special type of picture of the part of your body the doctor wants to look at.
Why do I need to have an Ultrasound?
The pictures of your body parts that the doctor needs to see sometimes cannot be seen by an X-Ray, so an ultrasound needs to be used.
What does an Ultrasound machine look like?
An ultrasound machine looks like a computer. The sonographer (the person taking the picture) uses a smooth flat wand and a special gel to take the picture. The gel and wand lets the computer hear the sound waves from your body. The pictures are sent to a special computer for the radiologist to look at. The radiologist is a special doctor who looks at the ultrasound pictures.
What happens when I have an Ultrasound?
A porter will come to bring you to the special room to have the ultrasound.  You will have to lift up your shirt so the sonographer can put the gel on your skin. They are very careful to make sure they do not get any gel on your clothes.
The technologist will put gel over the part of your body that the doctor wants to see. Next, she will move the smooth, flat wand over that part of your body. The wand is attached to the computer.  While the sonographer moves the wand over your body part, you will be able to see a wavy and fuzzy image on the screen. While she is moving the wand, she will also be touching buttons on the computer?s keyboard. Once the pictures are done, the technologist will wipe the gel off with a soft towel.
What will the Ultrasound feel like?
The ultrasound will not hurt, but it may tickle a little. The gel may feel a little cool and sticky.  The wand may press down onto your body a little bit, but it will not hurt.  Remember to lie still so they can get a clear picture. Thinking about your favourite thing to do may help you stay still. The sonographer may ask you to take a big breath in and hold it to help get a good picture.
Preparing for the test
Your nurse will give you the information you need to help you get ready to have your ultrasound. Depending on what they are taking a picture of, sometimes you are not allowed to eat anything before the ultrasound.
Other times they will tell you to drink a lot of water. This can help to make the picture they take clearer. While they are moving the wand over your stomach, you may feel that you have to go to the bathroom.  If you can, try to hold your pee until the test is done.  Don?t be afraid to tell someone if you cannot hold your pee. Once you tell the sonographer, they will do their best of finish taking pictures of your belly so you can go to the bathroom.
Sometimes you may have to do nothing to get ready for an ultrasound.
Remember
If you have any questions about the test, always ask!
This content has been reviewed and approved by health care team members at McMaster Children’s Hospital in Hamilton, Ontario. All content is for educational purposes only. For further information, please speak with your health care team.