What is Prostate Ultrasound “Transrectal Ultrasound (TRUS)”?
Transrectal ultrasound (TRUS) is an imaging procedure that is used to diagnose changes in the prostate and seminal vesicles. TRUS is a form of endoscopic ultrasound, a variant of sonography in which the transducer is inserted into the body, often with the help of an endoscope or probe.
During this examination, the transducer of an ultrasound probe “the size of a finger” is inserted through the anus into the rectum and positioned near the prostate. The prostate is located directly in front of the rectum and is particularly easy to examine with the TRUS. The transrectal ultrasound scan provides accurate images of the prostate, seminal vesicles, and their surroundings.
What are some common uses of the procedure?
- In the case of benign prostate enlargement, the ultrasound examination should preferably be carried out using TRUS. This mainly determines the volume of the prostate. This is used, among other things, to select the treatment method.
- If prostate cancer is suspected, i.e. if there is an increased Prostate-Specific Antigen (PSA) value or a conspicuous finding during the palpation examination, the TRUS can be used as a supplementary diagnosis for further clarification.
- A biopsy is required to confirm a suspicion of prostate cancer. The control of such sampling from the prostate is the main area of application of the TRUS.
- In certain stages of prostate cancer, no immediate treatment is carried out, but the tumor is observed (active surveillance).
- If prostate cancer is proven, i.e. after a positive biopsy, the staging of the tumor is determined by TRUS.
How does the procedure work?
In principle, ultrasound is emitted from a probe into the tissue and received again in the ultrasound examination of humans. The sound penetrates the body tissue and is reflected on various structures. From the duration of the sound until it returns to the probe, a computer can calculate an image that is displayed in gray levels on a screen and which the doctor can interpret more easily than just numbers. In the air, the sound would be reflected immediately, so that the transition from the probe to the body is made possible with a gel without disturbing air.
How is the procedure performed?
Like the digital rectal examination (DRE), the transrectal ultrasound examination is painless as long as there are no painful changes in the rectum area. The examination only takes a few minutes and is carried out on an outpatient basis.
Before the examination, a local anesthetic, sterile and disinfecting lubricant gel, will be instilled into the anus and rectum. After an exposure time of 5 – 10 minutes, the ultrasound probe is inserted into the rectum like a finger. By gently moving the probe, the doctor sets the areas to be examined that are visible on the monitor. Photo documentation can be made of the findings on the monitor during the examination. Patients should not expect pain or complications during or after the procedure.