During a testicular scan, the tracer substance is injected into a vein in the arm. It travels through the bloodstream to the testicles . Areas of the testicles where the tracer accumulates in abnormal amounts may indicate some types of tumors. The tracer may also indicate a pocket of fluid ( cyst ) or infection ( abscess ).
A testicular scan may be done in an emergency to evaluate the cause of sudden, painful swelling of a testicle, which can be caused by a twisted spermatic cord inside the testicle. This condition is called testicular torsion and needs immediate medical evaluation and treatment.
Testicular ultrasound has largely replaced testicular scans to investigate possible testicular tumors and testicular torsion.
Why It Is Done
A testicular scan is done to:
- Determine the cause of a painful, swollen testicle.
- Assess the damage to the testicles caused by an injury.
- Assess the flow of blood within the testicles.
How To Prepare
No special preparation is needed for a testicular scan.
You may be asked to sign a consent form before the test. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .
How It Is Done
You will need to remove any jewelry that might interfere with the scan. You may need to take off all or most of your clothes, but you will be given a cloth or paper covering to use during the test.
The technologist cleans the site on your arm where the radioactive tracer will be injected. A small amount of the radioactive tracer is then injected.
You will lie on your back on a table and your penis will be taped to your abdomen to prevent it from interfering with the scan. A sling or towel may be used to support the testicles under the scanner. After the radioactive tracer is injected, the camera will scan for radiation released by the tracer and produce pictures of the tracer in your testicles. Two scans are done about 15 minutes apart. You need to lie very still during each scan to avoid blurring the pictures. The camera does not produce any radiation, so you are not exposed to any more radiation while the scan is being done.
A testicular scan takes about 45 minutes.
How It Feels
You may feel nothing at all from the needle puncture when the tracer is injected, or you may feel a brief sting or pinch as the needle goes through the skin. Otherwise, a testicular scan is usually painless. You may find it uncomfortable to remain still during the scan, especially if your testicles are sore. Ask for a pillow or blanket to make yourself as comfortable as possible before the scan begins.
Allergic reactions to the radioactive tracer are rare. Most of the tracer will be eliminated from your body (through your urine or stool) within a day, so be sure to promptly flush the toilet and thoroughly wash your hands with soap and water. The amount of radiation is so small that it is not a risk for people to come in contact with you following the test.
Occasionally, some soreness or swelling may develop at the injection site. These symptoms can usually be relieved by applying moist, warm compresses to your arm.
There is always a very slight risk of damage to cells or tissue from being exposed to any radiation, including the low level of radiation released by the radioactive tracer used for this test.
A testicular scan uses a camera to take pictures of the testicles after a radioactive tracer accumulates in testicular tissues (nuclear medicine test). The results of a testicular scan are usually available within 2 days. In an emergency, results can be available within an hour.
The radioactive tracer flows evenly through the testicles. No accumulations of the tracer are found in any area of the testicles.
The tracer does not flow evenly through the testicles, indicating narrowing of, blockage of, or damage to the blood vessels in the testicles. This could indicate that blood flow has been reduced by a twisted spermatic cord inside the testicle. This is called testicular torsion .
Areas where the tracer accumulates in an abnormal amount could indicate a condition such as a cyst , tumor, pocket of infection ( abscess ), a blood clot, or inflammation of the tubes (ducts) that carry sperm (epididymis). This is called epididymitis .
What Affects the Test
The results of a testicular scan may not be accurate if you cannot remain still during the test.
What To Think About
- Testicular ultrasound has largely replaced testicular scans to investigate possible testicular torsion or tumors in the testicles. For more information, see the topic Testicular Ultrasound.
- Abnormal results from a testicular scan may be further investigated by other tests, such as a testicular biopsy , an ultrasound test, or X-ray tests.
- If a testicular scan is done for a young boy, a parent can accompany him while the test is being done.
Other Works Consulted
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||Christopher G. Wood, MD, FACS - Urology, Oncology|
|Last Revised||January 31, 2011|
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