Ultrasound imaging of the scrotum provides images of the testicles and the surrounding tissues. This is the primary imaging method used to evaluate disorders of the testicles, epididymis, which is a tube immediately next to a testis that collects sperm made by the testicle, and scrotum.

A Doppler ultrasound study may be part of this ultrasound examination. Doppler ultrasound is a special ultrasound technique that evaluates blood flow through a blood vessel.

Ultrasound imaging 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 the images for the exam.

Ultrasound is painless and non-invasive.

Your medical provider may recommend an ultrasound of the scrotum 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
• evaluate the cause of infertility
• look for the location of undescended testis.

Ultrasound can often detect an absent or undescended testicle as well. The testicle normally migrates from the abdomen, down the inguinal canal and then into the usual position in the scrotal sac. If it is not present, it may have stopped on its way and lie in the inguinal region, in which case the ultrasound will often see it.

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 can be moved into the scrotum. If left in the abdomen too long, it may become cancerous and may need to be removed.

Ultrasound can identify testicular torsion, which is the twisting of the spermatic cord that contains the vessels that supply blood to the scrotum. Caused by abnormally loose attachments of tissues that are formed during the 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 testes.

Ultrasound of the scrotum also can be used to locate and evaluate masses in the testicle or 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.

For most ultrasound exams, you will lie on your back on an exam table. You may have your position adjusted to either side in order to improve the quality of the images captured during the exam.

An ultrasound technologist will apply a warm water-based gel to the area of the body being studied. The gel will help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin that can block the sound waves from passing into your body. The transducer is placed on the body and moved back and forth over the area of interest until the desired images are captured.

There is usually no discomfort from pressure as the transducer is pressed against the area being examined. However, if scanning is performed over an area that is tender or sensitive, you may feel some pressure or minor discomfort from the transducer.

Once the exam is complete, the clear ultrasound gel will be wiped off your skin. Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain or discolor clothing.

Typically, ultrasound imaging of the scrotum takes approximately 45 to 60 minutes to complete.