Test Overview
A testicular scan uses a camera to take
pictures of the
testicles after a
radioactive tracer accumulates in testicular tissues
(nuclear medicine test).
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
A testicular scan is usually done by a
nuclear medicine technologist. The scan pictures are usually interpreted by a
radiologist or
nuclear medicine specialist.
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.
Risks
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 putting a warm, moist cloth on 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.
Results
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 1 hour.
Testicular scan
| Normal: |
The radioactive tracer flows evenly through
the testicles. No accumulations of the tracer are found in any area of the
testicles.
|
| Abnormal: |
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), blood clot, or inflammation of the tubes
(ducts) that carry sperm (epididymis). This inflammation 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 be with him.
References
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.
Credits
|
By
|
Healthwise Staff |
|
Primary Medical Reviewer
|
E. Gregory Thompson, MD - Internal Medicine |
|
Specialist Medical Reviewer
|
Christopher G. Wood, MD, FACS - Urology, Oncology |
|
Last Revised
|
December 28, 2012 |