| Ultrasound of the Thyroid Gland
What is an Ultrasound of the Thyroid? Back to Top
Ultrasound
imaging, also called ultrasound scanning or sonography, is a method of
obtaining images of internal organs by sending high-frequency sound
waves into the body. The reflected sound waves produce echoes that are
displayed and recorded as a real-time, visual image. No ionizing
radiation (x-ray) is involved in ultrasound imaging.
Because ultrasound images are captured in real-time, they can show
movement of internal tissues and organs, and enable physicians to see
blood flow. As a result, ultrasound can help to diagnose a variety of
conditions and to assess organ damage following illness. Ultrasound
imaging can help a physician determine the source of pain, swelling, or
infection in many parts of the body.
Ultrasound is a painless, useful way of examining many of the body's internal organs, including the thyroid.
What are some common uses of the procedure? Back to Top
A
physician may use an ultrasound examination of the neck to help
diagnosis a lump in the thyroid or a thyroid that is not functioning
properly. The thyroid gland is located in front of the neck just below
the Adam's apple and is shaped like a butterfly, with two lobes on
either side of the neck connected by a narrow band of tissue. It is one
of nine endocrine glands located throughout the body that make and send
hormones into the bloodstream. These hormones target specific body
functions and affect virtually every organ, tissue and cell in the body.
The thyroid gland produces thyroid hormones. Thyroid hormones set
the rate at which your body carries on its necessary functions
(metabolic rate). Some of the functions controlled by thyroid hormones
include heart rate, cholesterol level, body weight, energy level,
muscle strength, skin condition and vision.
The most common diseases of this gland result when the thyroid
becomes overactive or underactive. An overactive thyroid, also called
hyperthyroidism and Grave's disease, produces more thyroid hormone than
is needed. The underactive thyroid, called hypothyroidism, does not
produce enough hormone. Other common conditions of the thyroid include
an enlarged thyroid, often called a goiter, and lump in the gland.
How should I prepare for the procedure? Back to Top
You should wear comfortable, loose-fitting clothing for your ultrasound exam.
What does the ultrasound equipment look like? Back to Top
Ultrasound
scanners consist of a console containing a computer and electronics, a
video display screen and a transducer that is used to scan the body.
The transducer is a small hand-held device about the size of a bar of
soap, attached to the scanner by a cord. The physician or technologist
will spread a gel on the area of your body that is to be examined that
will allow the transducer to move around easily. The technologist will
then press the transducer firmly against the skin.
Ultrasound images are immediately visible on a nearby screen that
looks much like a computer or television monitor. The physician or
technologist will watch this screen during your examination and record
images that can be stored and viewed again. The patient is often able
to see the monitor and ultrasound images as well.
How does the procedure work? Back to Top
Ultrasound imaging
is based on the same principles involved in the sonar used by bats,
ships at sea, and anglers with fish detectors. As the sound passes
through the body, echoes are produced that can be used to identify how
far away an object is, how large it is, its shape, and its consistency
(fluid, solid or mixed).
The ultrasound transducer functions as both a generator of sound
(like a speaker) and a detector (like a microphone). When the
transducer is pressed against the skin, it directs inaudible,
high-frequency sound waves into the body. As the sound echoes from the
body's fluids and tissues, the transducer records the strength and
character of the reflected waves—with Doppler ultrasound the microphone
captures and records tiny changes in the sound wave's pitch and
direction of the sound. These echoes are instantly measured and
displayed by a computer, which in turn creates a real-time picture on
the monitor. The live images of the examination are usually recorded
for a permanent record.
How is the procedure performed? Back to Top
You will be
positioned on an examination table. A clear gel will then be applied to
your neck, to help the transducer make secure contact with the skin.
The sound waves produced by the transducer cannot penetrate air, so the
gel helps eliminate air pockets between the transducer and the skin.
The technologist or radiologist presses the transducer firmly against
the skin and sweeps it back and forth over the thyroid area. When the
examination is complete, the patient may be asked to dress and wait
while the ultrasound images are reviewed. Often, though, the
technologist or radiologist is able to review the ultrasound images in
real-time as they are acquired, and the patient can be released
immediately.
What will I experience during the procedure? Back to Top
Most
ultrasound examinations are painless, fast, and easy. You will lie on
your back on an examining table. The technologist or doctor will spread
some warm gel on your skin and then press the transducer firmly against
your neck, moving it until the desired images are captured. The
examination usually takes less than 30 minutes.
Who interprets the results and how do I get them? Back to Top
A
radiologist, who is a physician experienced in ultrasound and other
radiology examinations, will analyze the images and send a signed
report with his or her interpretation to your primary care physician,
who will then give you the results. In some cases the radiologist may
discuss preliminary results with you at the conclusion of your
examination.
What are the benefits vs. risks? Back to Top
Benefits
- Ultrasound scanning is noninvasive (no needles or injections, in most cases) and is usually painless.
- Ultrasound is widely available.
- Ultrasound uses no ionizing radiation.
- Ultrasound images can visualize structure, movement and live function in the body's organs and blood vessels.
Risks
- There are no known harmful effects for diagnostic ultrasound.
What are the limitations of an Ultrasound of the Thyroid? Back to Top
You will need to extend your neck to gain appropriate access, which may be mildly uncomfortable. Back to Top |
