Test Overview
A
salivary gland scan uses a special camera and a
tracer (radioactive chemical) to take pictures of the
salivary glands. This can help your doctor find the cause of dry mouth (xerostomia) or swelling in the salivary glands.
During a salivary gland scan, the tracer liquid is put into a vein (IV) in your arm. The tracer moves through your blood
and into the salivary glands. A special camera takes pictures to show how much
tracer stays in the salivary glands.
Why It Is Done
A salivary gland scan is done
to:
- Find the cause of swelling in the major salivary glands. Swelling
may be caused by an infection (abscess),
inflammation, or a pocket of fluid (cyst).
- See if a growth in the
parotid gland is a benign tumor or may be cancer.
- Find the
cause of dry mouth (xerostomia). Several problems can cause
dry mouth, such as a blocked salivary duct, a growth in a salivary gland, or
Sjögren's syndrome.
How To Prepare
Before the salivary gland scan, tell
your doctor if you:
- Are or might be pregnant.
- Are
breastfeeding. The radioactive tracer used in this test can get into your breast milk. Do not breastfeed your baby for 2 days after this test. During this time, you can give your baby breast milk you stored before the test, or you can give formula. Discard the breast milk you pump for 2 days after the test.
- Have had other nuclear scans
recently. If so, the salivary gland scan may need to be delayed.
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 may
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 salivary gland scan is usually done
by a nuclear medicine technologist. The pictures are usually interpreted by a
radiologist or
nuclear medicine specialist.
You will need to take off jewelry that may get in the way of the scan.
During a salivary
gland scan, you will sit with the camera placed at your neck. A small amount of
the
tracer is put in your vein (IV).
The
camera will scan for radiation released by the tracer. The pictures are taken
every few minutes during the scan. You need to stay very still during the scan
so the pictures are not blurry.
You may be asked to suck on a
lemon after the first pictures are taken. This causes your salivary glands to
release more saliva. Then more pictures are taken.
A salivary
gland scan takes about 1 hour.
How It Feels
You will not feel pain during the test. You may feel a quick sting or pinch when the IV is put in your arm. The tracer may make you feel warm and flushed.
You may find it hard to lie still during the
scan.
Risks
There is a slight chance of damage to cells or
tissue from radiation, including the low levels of radiation used for this
test. But the chance of damage from the X-rays is usually very low compared
with the benefits of the test.
Allergic reactions to the tracer are very rare.
In some cases,
soreness or swelling may develop at the IV site. Apply a moist, warm compress
to your arm to relieve these symptoms.
Results
A
salivary gland scan uses a special camera and a
tracer (radioactive chemical) to take pictures of the
salivary glands.
The results of a salivary gland scan are usually
available within 2 days.
Salivary gland scan| Normal:
| The tracer moves evenly
through the salivary glands and is released normally into the mouth. |
|---|
The salivary ducts leading
from the salivary glands are not blocked. Saliva is released in response to
sucking on a lemon. |
| Abnormal:
| The tracer does not move
evenly through the salivary glands. A pocket of fluid (cyst), a pocket
of infection (abscess), or a tumor or other growth may be
present. |
|---|
The tracer may not flow
normally from the salivary glands into the mouth. This may be caused by a tumor
pressing on the duct, a stone in the duct, or inflammation of the
duct. |
The flow of tracer through the
salivary glands is decreased. This may point to a condition, such as
Sjögren's syndrome. |
The amount of tracer in the
salivary glands in front of the ear is greatly increased. This may indicate
inflammation or infection of the parotid glands (parotitis). |
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Pregnancy. A salivary gland scan is not usually
done during pregnancy, because the radiation could harm the
developing baby (fetus).
- The inability to stay still during the test.
What To Think About
- In North America, a salivary gland scan is
rarely done. Most often, a
CT scan or
magnetic resonance imaging (MRI) is done to look at
the salivary glands. An
ultrasound scan also may be done to look at the
salivary glands. But a salivary scan is the only test that can see how well the
salivary glands are working.
- Although a salivary gland scan may be
done to evaluate dry mouth caused by
Sjögren's syndrome, it usually is not used to diagnose
this disease. But a salivary gland scan may be used to diagnose Sjögren's
syndrome in a person who has
rheumatoid arthritis.
References
Other Works Consulted
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Credits
ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Specialist Medical ReviewerHoward Schaff, MD - Diagnostic Radiology
Current as ofOctober 14, 2016