Transrectal Ultrasound - Uses, Preparation, Procedure, and Limitations

What Is Transrectal Ultrasound?

Transrectal ultrasound (TRUS) is a simple and safe test used to examine the prostate gland in detail. A small ultrasound probe is gently placed a short distance inside the rectum because it sits right behind the prostate. This position helps doctors get clear pictures of the prostate using sound waves, not radiation. The test helps find the size of the prostate, any lumps, or signs of cancer. It is also used to guide biopsies, where tiny samples are taken for testing. The procedure usually takes only a few minutes and may feel slightly uncomfortable, but it is not painful for most people.

What Are the Uses of Transrectal Ultrasound?

Transrectal ultrasound in prostate cancer is beneficial, as it helps doctors see the prostate clearly. Transrectal ultrasound is useful in the following conditions.

• To detect prostatitis (swelling of the prostate gland).

• To detect prostate cancer (an abnormal mass within the prostate).

• Find the cause of infertility in men.

• Diagnosis of benign prostatic hyperplasia (BPH) [a noncancerous condition in which the prostate gland becomes large in size].

• Determine the size of the prostate gland.

• Determine whether prostate cancer has spread to lymph nodes or other body parts.

• Guiding tool in the biopsy.

It is also useful in the diagnosis of the following symptoms:

• The presence of a nodule in the prostate is felt during physical examination.

• High PSA (prostate-specific antigen) level in the blood.

How to Prepare for a Transrectal Ultrasound?

Patients may need to stop taking antiplatelet medicines (blood-thinning drugs) like Aspirin 7 to 10 days before the transrectal ultrasound procedure if a biopsy is planned.

• An enema (a medicine used to clean the bowel) may be administered before the procedure.

• Emptying the bladder before the scan.

• Have a light meal before the procedure.

How Is the Transrectal Ultrasound (TRUS) Performed?

Patients are instructed to undress below their waist and asked to lie on their side for transrectal ultrasounds. The correct transrectal ultrasound position is the decubitus position (with their knees bent on the procedure table). A disposable cover is placed over the transducer, which is lubricated with gel to facilitate easy insertion.

• This procedure utilizes a long transducer to generate sound waves at a frequency of approximately 8 to 10 MHz. Modern transducers operate at frequencies ranging from 5 to 10 MHz (megahertz).

• The doctor may inspect the anus and perineal area (space between the anus and scrotum) before inserting the transducer for any hindrances such as hemorrhoids (inflammation of the rectal veins), skin problems, or anal issues. They slowly insert the transducer through the anus. Patients may feel slight pressure, but it is painless.

• Images are taken from different angles to get better images. Images of the prostate and the surrounding tissues will appear on the screen.

• After the procedure, patients may see a small amount of blood in the urine or semen. This procedure is completed within 20 minutes.

How Is the Transrectal Ultrasound Prostate Biopsy Done?

• A prostate biopsy is done when someone has symptoms of prostate cancer or a high PSA level.

• If the PSA is above 10, the risk of prostate cancer can be more than 50%.

• In a transrectal ultrasound biopsy, the doctor first numbs the area with local anesthesia.

• An ultrasound probe is placed in the rectum to help the doctor see the prostate clearly.

• A thin needle is then passed through the rectum into the prostate.

• The needle takes small tissue samples from the prostate.

• These samples are examined under a microscope to detect cancer.

• Patients are given antibiotics before and after the test to prevent infection.

• Sometimes the biopsy is standard even if the ultrasound looks abnormal.

• In that case, the biopsy may need to be repeated after 6 to 12 months.

What Are the Interpretations of Transrectal Ultrasound (TRUS)?

The rectal ultrasound produces sound waves and sends them to the prostate gland. The normal and abnormal tissue send back different kinds of echoes. These echoes are processed in the computer, which translates them into a video picture of the prostate, which indicates the following:

1. Isoechoic Zones - Areas of normal tissue will bounce back the same number of sound waves that they received.

2. Hypoechoic Zones - Hypoechoic areas will send back fewer echoes than they received and often indicate the presence of cancer.

3. Hyperechoic Zones - Hyperechoic areas will send back considerably more echoes than they received, which indicates the presence of prostatic calcifications or stones in the prostate. The stones are harmless unless infected.

What Is the Limitation of Transrectal Ultrasound?

Transrectal ultrasound cannot be performed in patients who have undergone surgery to remove their rectum because this procedure places the transducer through the rectum. In such conditions, regular ultrasound or magnetic resonance imaging (MRI) of the pelvis may be recommended.

Conclusion

Transrectal ultrasound is beneficial as it gives a clear image of the prostate. It makes it easier to find problems and safely guide a biopsy when needed. Although it cannot catch every small or early cancer, it is still an important and reliable first step in checking prostate health.

Key Takeaways

• TRUS is a safe and straightforward test to look at the prostate.

• It helps doctors find unusual areas and guide a biopsy accurately.

• The test is short, usually not painful, and done with local numbing.

• Sometimes, more tests are needed because TRUS may miss very small cancers.

To get a detailed explanation, talk to our doctor.