| Ultrasound of the Prostate
What is Prostate Ultrasound Imaging? Back to Top
Ultrasound
or sonography involves sending sound waves into the body. These sound
waves reflect off the internal organs and are recorded by special
instruments that create images of anatomic parts. No ionizing radiation
(x-ray) is involved in ultrasound imaging. Ultrasound images are
captured in real time so they can show movement of internal tissues and
organs, such as the flow of blood in arteries and veins.
Prostate ultrasound is used to detect possible disorders within a
man's prostate gland. Ultrasound images can indicate when the prostate
is enlarged or when there is an abnormal growth that might be cancer.
What are some common uses of the procedure? Back to Top
For
men, a transrectal ultrasound of the prostate gland may be warranted if
a blood test result is elevated or if a nodule is felt by a physician
during a routine physical exam or prostate cancer screening exam. An
ultrasound exam can also indicate other types of prostate conditions,
such as inflammation of the prostate, or it can be used to help
diagnose the reasons for a man's infertility.
Because ultrasound provides real-time images, it also can be used to
guide procedures, such as needle biopsies, in which a needle is used to
sample cells from an abnormal area for laboratory testing.
How should I prepare for the procedure? Back to Top
You
should wear comfortable, loose-fitting clothing for your ultrasound
exam. An enema is taken two to four hours before the ultrasound to
clean out the bowel. Follow your doctor's instructions on bowel
preparation. A full bladder helps with visualization of the prostate
gland, so you may be asked to drink up to six glasses of water prior to
your exam.
What does the equipment look like? Back to Top
The equipment
consists of a transducer and a monitoring system. The transducer is a
small, cylinder-shaped probe, which is lubricated and inserted into the
rectum to view the prostate or to assist with an ultrasound-guided
biopsy, if cancer is suspected.
The ultrasound image is immediately visible on a nearby screen that
looks much like a computer or television monitor. The radiologist or
sonographer watches this screen during the examination and captures
representative images for storage. Often, the patient is able to see
the screen as well.
How does the procedure work? Back to Top
Ultrasound imaging
is based on the same principles as the sonar used by bats, ships at sea
and anglers with fish detectors. As a controlled sound wave bounces
against objects, its echoing waves can be used to identify how far away
the object is, how large it is, its shape and its internal consistency
(fluid, solid or mixed).
The ultrasound transducer functions as both a loudspeaker (to
transmit sounds) and a microphone (to record the sounds). When the
transducer is inserted into the rectum it directs a stream of
inaudible, high-frequency sound waves into the body. As the sound waves
echo back from the body's fluids and tissues, the sensitive microphone
in the transducer records the strength and character of the reflected
waves.
How is the procedure performed? Back to Top
In men, the
prostate gland is located directly in front of the rectum, so the
ultrasound exam is performed transrectally. A protective cover is
placed over the transducer, it is lubricated, and then placed into the
rectum so the sound need only travel a short distance from the
prostate. The images are obtained from different angles to get the best
view of the prostate gland. Ultrasound of the prostate is most often
performed with the patient lying on his left side with his knees bent
up slightly.
If a suspicious lesion is identified with ultrasound or with a
rectal examination, an ultrasound-guided biopsy can be performed. This
procedure involves advancing a needle into the prostate gland while the
radiologist watches the needle placement with ultrasound. A small
amount of tissue is taken for microscopic examination.
When the examination is complete, the patient may be asked to dress
and wait while the ultrasound images are reviewed, either on film or on
a monitor. Often the sonographer 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
If
no biopsy is required, transrectal ultrasound of the prostate is
similar in discomfort to a rectal exam performed by your doctor. The
examination usually takes about 15 to 25 minutes.
If a biopsy is performed, additional discomfort, due to the needle
insertion, is usually minimal because the rectal wall is relatively
insensitive in the region of the prostate. A biopsy will add time to
the procedure.
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.
Usually you will receive the ultrasound results from the physician who
ordered the test. In some cases the radiologist may discuss preliminary
results with you at the conclusion of your examination. New technology
also allows for distribution of diagnostic reports and referral images
over the Internet at many facilities.
What are the benefits vs. risks? Back to Top
Benefits
- Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies.
- Ultrasound is widely available.
- Ultrasound uses no ionizing radiation.
- Ultrasound can visualize structure, movement and function in the body's organs and blood vessels.
Risks
- For standard diagnostic ultrasound there are no known harmful effects on humans.
What are the limitations of Prostate Ultrasound Imaging? Back to Top
Men
who have had recent surgery on their bowel are not good candidates for
ultrasound of the prostate gland because this type of ultrasound
requires placing a probe into the rectum. In addition, ultrasound waves
are reflected by air or gas, therefore ultrasound is not an ideal
imaging exam for the bowel. Barium exams and CT scanning may be the
methods of choice for bowel-related problems. Back to Top |
