Testicle ultrasound is an imaging test that examines the testicles and other parts inside the scrotum. The testicles are the male reproductive organs that produce sperm and the hormone testosterone. They are located in the scrotum, the flesh-covered sac that hangs between the legs at the base of the penis.

You lie on your back with your legs spread. The health care provider drapes a cloth or applies wide strips of adhesive tape across your thighs under the scrotum. The scrotal sac will be slightly raised, with the testicles lying side by side.

A clear gel is applied to the scrotal sac to help transmit the sound waves. A handheld probe (the ultrasound transducer) is then moved over the scrotum. The ultrasound machine sends out high-frequency sound waves, which reflect off areas in the scrotum to create a picture.

No special preparation is needed for this test.

For children, the preparation you can provide for this test depends on your child's age, past experiences, and level of trust. For specific information on how to prepare your teen, see adolescent test or procedure preparation (12 - 18 years). This test is rarely done on children younger than age 12.

There is little discomfort. The conducting gel may feel slightly cold and wet.

The ultrasound is done to help determine why one or both testicles have become larger, or to find the reason for pain in the testicles.

The testicles and other areas in the scrotum appear normal.

Possible causes of abnormal results include:

• Infection with or without abscess
• Noncancerous (benign) cyst
• Testicular torsion
• Testicular tumor

There are no known risks. You will not be exposed to ionizing radiation with this test. Ionizing radiation procedures such as x-ray carry a small cancer risk and may damage sperm, but this test does not.

In certain cases, Doppler ultrasound may help identify blood flow inside the scrotum. For example, Doppler ultrasound is very helpful in cases of testicular torsion, because blood flow to the twisted testicle may be reduced.

Richie JP, Steele GS. Neoplasms of the testis. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 29.