Transrectal ultrasound scan (TRUS)

A transrectal ultrasound scan (TRUS) is an examination of the prostate gland using ultrasound. 

What is a TRUS?

Ultrasound scans use high frequency sound waves to create a picture of a part of the body. A prostate ultrasound scan can show up changes in your prostate, including abnormal growths.

The ultrasound scanner has a microphone that gives off sound waves. The sound waves bounce off the organs inside your body, and the microphone picks them up. The microphone links to a computer. This turns the sound waves into a picture on the screen.

You might have a sample of tissue taken from the prostate gland (biopsy) at the same time. This is called transrectal ultrasound (TRUS) guided biopsy. 

Preparing for the scan

You usually have this scan in the hospital x-ray department.

You need to make sure your bowel is empty when you go for your appointment. You might need to have an enema to empty your bowel. An enema is a liquid that you put into your back passage (rectum).

Or you might have a liquid medicine to swallow the day before. You need to stay close to a toilet for a few hours after taking the medicine.

Check your appointment letter to find out how to prepare for your scan.

What happens

When you arrive at the department a staff member asks you to take your lower clothes off and change into a hospital gown.

You lie down on the scan table. They usually ask you to lie on your left side with your knees pulled up towards your chest.

Your doctor or sonographer puts a small ultrasound probe into your back passage. They use a cold lubricating gel. The gel makes it easier for the probe to move around.

Diagram showing a Transrectal ultrasound

The probe produces sound waves to create a clear picture of the prostate gland. This test is uncomfortable but shouldn't hurt. It doesn’t take long.

After the scan

You can get dressed and should be able to go home straight away.

Getting your results

Waiting for results can make you anxious. You can ask your doctor or nurse how long it will take to get the results. Contact the doctor who arranged the test if you haven't heard anything after a couple of weeks. It might help to talk to a close friend or relative about how you feel.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.

Possible risks

Ultrasound scans are very safe procedures. They don't involve radiation. But you might have slight soreness in the back passage for a couple of days.

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