What Is a Prostate Ultrasound? What to Expect During a Transrectal Ultrasound (TRUS)
Key takeaways:
Along with a biopsy, prostate ultrasounds help diagnose prostate cancer.
A probe is placed into the rectum during a prostate ultrasound in order to get images of the prostate.
Your oncology team may be able to do a prostate ultrasound at their office and offer real-time results.
Table of contents
A prostate ultrasound is an important tool used to diagnose and monitor prostate cancer. If you’re having a prostate ultrasound, keep reading to learn what you need to know about how prostate ultrasounds work and how to prepare for one.
What is a prostate ultrasound (TRUS)?
A prostate ultrasound, also known as a prostate sonogram or transrectal ultrasound (TRUS), is an imaging study used to look at the size and shape of the prostate. The prostate is an organ that’s inside the pelvis, just below the bladder. Because of its location, a healthcare professional can’t directly examine or look at the prostate. That’s where an ultrasound comes in.
How does a prostate ultrasound work?
An ultrasound is an imaging test that uses sound waves to create a picture. For the prostate ultrasound, a small and lubricated probe is placed into the rectum. The probe is about the size of an adult’s index finger. The probe creates sound waves, which then enter the prostate. The echoes from these sound waves make a black-and-white image on the ultrasound screen that both you and your healthcare team can see.
What are the benefits of a prostate ultrasound?
Ultrasound studies are great tools for several reasons:
No radiation: Unlike CT scans or X-rays, ultrasounds don’t use radiation to create a picture.
Images in real time: Your team can see the images of your prostate as they’re doing the ultrasound. This means that they can make sure they’re getting the images they need. It also means you can get some information in real-time and some answers before you even leave the office.
Convenience: Ultrasound machines are compact, so some healthcare teams have them in their office. This means you might not need to go to a special imaging center to have the test done.
Search and compare options
Who needs a prostate ultrasound?
A prostate ultrasound is used to “see” the prostate gland or surrounding structures. Prostate ultrasounds can be used to evaluate several medical conditions including:
Prostatitis (prostate gland inflammation)
Male factor infertility
Your healthcare team may also recommend a prostate ultrasound if you have high levels of prostate-specific antigen (PSA) or you have unexpected findings on a digital rectal exam.
Can you tell the stage of prostate cancer from a prostate ultrasound?
A prostate ultrasound can’t tell the stage of prostate cancer. In fact, a prostate ultrasound can’t be used to diagnose prostate cancer on its own because it can’t pick up certain prostate tumors.
Most often, a prostate ultrasound helps a surgeon perform a prostate biopsy. A surgeon uses a prostate ultrasound to help guide needle placement during a prostate biopsy. Prostate biopsies can help diagnose prostate cancer and give a stage.
How do you prepare for an ultrasound?
The good news is prostate ultrasounds don’t require too much preparation. There are a few things a healthcare professional might ask you to do in preparation:
Stop certain medications: If you’re getting a biopsy at the same time as your ultrasound, you’ll need to stop taking any blood thinners or aspirin a week before the ultrasound.
Give yourself an enema: You may be asked to give yourself an enema either the night before or the morning of your ultrasound. This will remove any stool and gas from your rectum so it doesn’t get in the way when the probe is getting images of your prostate.
Take OTC pain relievers: You won’t need anesthesia if you’re just having an ultrasound. You might want to consider taking an over-the-counter (OTC) pain medication, like acetaminophen, 1 hour before your ultrasound to help with discomfort.
Wear comfortable clothing: You’ll want to wear clothing that’s easy to remove on the day of your ultrasound. You’ll need to change into a gown for your ultrasound.
Who needs prostate cancer screening? Learn more about prostate cancer screening.
Early signs of prostate cancer: Take a look at the most common symptoms of prostate cancer.
What is a prostatectomy? Review the types of surgery used to treat prostate cancer.
What can you expect during a prostate ultrasound (TRUS)?
A prostate ultrasound takes about 10 to 15 minutes. But when planning your day, don’t forget to add in time for things like check-in, registration, and possible office delays.
Here’s what you can expect during your ultrasound:
You’ll be asked to change into a hospital gown.
You’ll be asked to lie on your side or back with your knees bent on the exam table.
A covered and lubricated ultrasound probe, which is about the width of your index finger, will be inserted into your anus and then moved up into your rectum.
A healthcare professional will see images of your prostate on the screen. You may be able to see the screen, too.
The healthcare professional will need to turn the probe several times to look at different parts of your prostate and surrounding structures. You’ll feel pressure in your rectum as this happens. This may be uncomfortable but shouldn’t be painful.
Since there’s lubricating gel on the probe, you may feel the cool gel along with the pressure from the probe.
What should I expect after a prostate ultrasound?
After the ultrasound, your healthcare team will go over the images with you. Sometimes a radiologist reviews the images and writes a report. In these cases, your healthcare team will call you in 1 to 3 days to review your results.
Otherwise, you don’t need any special care after the ultrasound, and you can return to your normal activities. You may continue to feel some pressure or coolness from the gel for a few hours — this is normal.
Complications from prostate ultrasounds alone rarely, if ever, happen. But just to be safe — call your healthcare team after your ultrasound if you have:
Fever
Pain
Blood in your stool, urine, or semen
Frequently asked questions
You’ll need a full bladder if you’re getting a transabdominal ultrasound. If the bladder isn’t full, it may be more difficult to see the prostate. But you don’t need a full bladder for a transrectal ultrasound (TRUS).
Ultrasounds themselves are painless. But you may experience mild discomfort while the probe is inside your rectum during a TRUS. The sensation should be similar to what you experience during a rectal exam. But a TRUS takes longer than a rectal exam.
The bottom line
A prostate ultrasound is a useful tool that can be used to diagnose conditions that affect the prostate. Along with a biopsy, a prostate ultrasound is an important part of prostate cancer diagnosis. Prostate ultrasounds are safe, quick, and require very little preparation.
Why trust our experts?
References
Catalona, W. J., et al. (1994). Comparison of digital rectal examination and serum prostate specific antigen in the early detection of prostate cancer: Results of a multicenter clinical trial of 6,630 men. The Journal of Urology.
Chen, F. K., et al. (2016). Utility of ultrasound in the diagnosis, treatment, and follow-up of prostate cancer: State of the art. The Journal of Nuclear Medicine.
National Institute of Diabetes and Digestive and Kidney Diseases. (2014). Prostatitis: Inflammation of the prostate. National Institute of Health.
Parkway Radiology. (2020). Ultrasound imaging of the prostate.
RadiologyInfo.org. (2024). Prostate ultrasound.
