Ultrasound - Scrotum

What is Ultrasound Imaging of the Scrotum?

Ultrasound imaging of the scrotum provides pictures of a male's testicles and the surrounding tissues.

Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. It is safe and painless. It produces pictures of the inside of the body using sound waves. Ultrasound imaging is also called sonography. It uses a small probe called a transducer and gel placed directly on the skin. High-frequency sound waves travel from the probe through the gel into the body. The probe collects the sounds that bounce back. A computer uses those sound waves to create an image. Ultrasound exams do not use radiation (x-rays). Because ultrasound captures images in real-time, it can show the structure and movement of the body's internal organs. The images can also show blood flowing through blood vessels.

What are some common uses of the procedure?

Ultrasound imaging of the scrotum is the primary imaging method used to evaluate disorders of the testicles, epididymis (tubes immediately next to the testicles that collect sperm made by the testicle) and scrotum.

This study is typically used to:

• determine whether a mass in the scrotum felt by the patient or doctor is cystic or solid and its location.
• diagnose results of trauma to the scrotal area.
• diagnose causes of testicular pain or swelling such as inflammation or torsion.
• evaluate the cause of infertility such as varicocele.
• look for the location of undescended testis.

A sudden onset of pain in the scrotum should be taken very seriously. A common cause of scrotal pain is epididymitis, an inflammation of the epididymis. It is treatable with antibiotics. If left untreated, this condition can lead to an abscess or loss of blood flow to the testicles.

Ultrasound can often detect an absent or undescended testicle as well. It is estimated that approximately three percent of full-term baby boys have an undescended testicle. The testicle normally migrates from the abdomen down a short passage called the inguinal canal and then into the usual position in the scrotal sac before birth. If not present in the scrotal sac, the testicle may have stopped in the inguinal region, in which case the ultrasound examination will often see it. If the testicle has not left the abdominal cavity, it may not be seen by sonography. If a testicle is not detected, a urologist may be consulted in order to decide whether additional imaging such as an MRI is needed to determine its location. If the testicle is found to be in the inguinal region, it may be moved into the scrotum. If left in the abdomen too long, the testicle may become cancerous and may need to be removed.

Ultrasound can identify testicular torsion, the twisting of the spermatic cord that contains the vessels that supply blood to the testicle. Testicular torsion is caused by abnormally loose attachments of tissues that are formed during fetal development. Torsion commonly appears during adolescence, and less often in the neonatal period, and is very painful. Torsion requires immediate surgery to avoid permanent damage to the testicle.

Ultrasound also can be used to locate and evaluate masses (lumps or tumors) in the testicle or elsewhere in the scrotum. Collections of fluid and abnormalities of the blood vessels may appear as masses and can be assessed by ultrasound. Masses both outside and within the testicles may be benign or malignant and should be evaluated as soon as they are detected.

How should I prepare?

Wear comfortable, loose-fitting clothing. You may need to remove all clothing and jewelry in the area to be examined.

You may need to change into a gown for the procedure.

No other preparation is required.

If your son is undergoing the examination, explain the procedure to him. In most cases, you will be able to accompany him into the examination room for support and reassurance.

What does the equipment look like?

Ultrasound machines consist of a computer console, video monitor and an attached transducer. The transducer is a small hand-held device that resembles a microphone. Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out inaudible, high-frequency sound waves into the body and listens for the returning echoes. The same principles apply to sonar used by boats and submarines.

The technologist applies a small amount of gel to the area under examination and places the transducer there. The gel allows sound waves to travel back and forth between the transducer and the area under examination. The ultrasound image is immediately visible on a video monitor. The computer creates the image based on the loudness (amplitude), pitch (frequency), and time it takes for the ultrasound signal to return to the transducer. It also considers what type of body structure and/or tissue the sound is traveling through.

In order to perform a scrotal sonogram, most commonly a linear small parts transducer is used.

How does the procedure work?

Ultrasound imaging uses the same principles as the sonar that bats, ships, and fishermen use. When a sound wave strikes an object, it bounces back or echoes. By measuring these echo waves, it is possible to determine how far away the object is as well as its size, shape, and consistency. This includes whether the object is solid or filled with fluid.

Doctors use ultrasound to detect changes in the appearance of organs, tissues, and vessels and to detect abnormal masses, such as tumors.

In an ultrasound exam, a transducer both sends the sound waves and records the echoing (returning) waves. When the transducer is pressed against the skin, it sends small pulses of inaudible, high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids and tissues, the sensitive receiver in the transducer records tiny changes in the sound's pitch and direction. A computer instantly measures these signature waves and displays them as real-time pictures on a monitor. The technologist typically captures one or more frames of the moving pictures as still images. They may also save short video loops of the images.

How is the procedure performed?

For most ultrasound exams, you will lie face-up on an exam table that can be tilted or moved. Patients may turn to either side to improve the quality of the images.

The radiologist (a doctor specifically trained to supervise and interpret radiology exams) or sonographer will position you on the exam table. They will apply a water-based gel to the area of the body under examination. The gel will help the transducer make secure contact with the body. It also eliminates air pockets between the transducer and the skin that can block the sound waves from passing into your body. The sonographer places the transducer on the body and moves it back and forth over the area of interest until it captures the desired images.

There is usually no discomfort from pressure as they press the transducer against the area being examined. However, if the area is tender, you may feel pressure or minor pain from the transducer.

Once the imaging is complete, the technologist will wipe off the clear ultrasound gel from your skin. Any portions that remain will dry quickly. The ultrasound gel does not usually stain or discolor clothing.

What will I experience during and after the procedure?

Most ultrasound exams are painless, fast, and easily tolerated.

Ultrasound imaging of the scrotum is usually completed within 15 to 30 minutes, though sometimes more time is necessary.

If you are accompanying your son during the procedure, ask him to lie still so the sound waves can produce the proper images.

Babies undergoing the examination might cry, but this should not interfere with the procedure.

When the exam is complete, the technologist may ask you to dress and wait while they review the ultrasound images.

After an ultrasound exam, you should be able to resume your normal activities immediately.

Who interprets the results and how do I get them?

A radiologist, a doctor trained to supervise and interpret radiology exams, will analyze the images. The radiologist will send a signed report to the doctor who requested the exam. Your doctor will then share the results with you. In some cases, the radiologist may discuss results with you after the exam.

You may need a follow-up exam. If so, your doctor will explain why. Sometimes a follow-up exam further evaluates a potential issue with more views or a special imaging technique. It may also see if there has been any change in an issue over time. Follow-up exams are often the best way to see if treatment is working or if a problem needs attention.

What are the benefits vs. risks?

Benefits

• Most ultrasound scanning is noninvasive (no needles or injections).
• Occasionally, an ultrasound exam may be temporarily uncomfortable, but it should not be painful.
• Ultrasound is widely available, easy to use, and less expensive than most other imaging methods.
• Ultrasound imaging is extremely safe and does not use radiation.
• Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
• Ultrasound provides real-time imaging. This makes it a good tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration.

Risks

• Standard diagnostic ultrasound has no known harmful effects on humans.

What are the limitations of Scrotal Ultrasound Imaging?

Ultrasound of the scrotum is helpful for finding abnormalities such as masses in the scrotum or testicles. However, it does not always permit an exact diagnosis (i.e., the exact type of tissue a mass is composed of, especially when the mass is solid). Blood flow images of the testicles are not always reliable in determining the presence or absence of blood supply to a testicle that has twisted. When searching for an absent testicle, ultrasound may not be able to find it if it is located in the abdomen because gas filled bowel loops may block the view.