Ultrasound and cancer diagnosis

PDF download is not available for Arabic and Urdu languages at this time. Please use the browser print function instead

An ultrasound is a scan that uses sound waves to create a picture of the inside of your body. Discover how an ultrasound is done, what to expect during the scan and when you get your results.

Key points

  • CT scans take a series of pictures that are then put together so the doctors can see different "slices" through your body.
  • You will need to remove any metal before a CT scan, change into a hospital gown and lie completely still during the scan.
  • A CT scan usually takes about 30 minutes.
  • You may need to drink or have an injection of contrast dye that will make the CT pictures clearer.
  • It may take up to a week before your get the results of the scan.

What is an ultrasound scan?

An ultrasound scan uses sound waves to make a picture of the inside of your body. The ultrasound scan is done by a sonographer, who is an expert in using ultrasound machines.

There is no exposure to radiation when you have an ultrasound. Ultrasounds are very safe.

How are ultrasound scans done?

Ultrasounds do not hurt and they are very safe. You can have an ultrasound in a hospital or a clinic. How you prepare for an ultrasound scan depends on what part of your body is being scanned. For some abdominal (belly) scans, you may need to stop eating and drink only clear liquids for four hours before the scan so that you have a full bladder.

The sonographer (ultrasound technician) will ask you to either loosen your clothes or change into a hospital gown. Then you will lie down on a bed. A family member can stay in the room with you. The ultrasound machine is a big box with a screen and is attached to a probe that looks like a microphone.

The sonographer will put gel on the probe and then will gently run it over the part of your body being scanned. The gel will feel cold but it is necessary to make a clear picture. The probe picks up sound waves from your body and the computer turns these into a picture. You may be able to see the picture on the screen. It looks like many white dots on a black background.

An ultrasound scan takes between 10 and 30 minutes. The scan will take multiple pictures.

The sonographer will show the pictures to a radiologist. You may need to wait until the radiologist looks at all the pictures to make sure they are clear enough. You may need to have more pictures taken. If they are clear enough, the scan is finished.

Ultrasound results

The radiologist will look at the pictures carefully and will send a report to your doctor. Your doctor will then tell you and your family what the pictures showed. It may be anywhere from a couple of days to a little over a week until you receive the ultrasound results.

Last updated: September 3rd 2019