Ultrasound
What is an Ultrasound exam?
An ultrasound exam is a painless medical test that helps physicians diagnose and treat medical conditions. Ultrasound is also used to detect changes in appearance and function of organs, tissues, or abnormal masses, such as tumors. It takes an image of internal organs in the body using high-frequency sound waves to produce pictures. Since ultrasound exams use sound waves and not X-rays, images are captured in real-time. These images can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.
How does it work?
Ultrasound imaging, sometimes called sonography, is based on the same principles involved in the sonar systems used on boats or submarines. When a sound wave strikes an object, it bounces backward, or "echoes." By measuring these echo waves it is possible to determine the object's size, shape, consistency and uniformity. It can also determine if the object is solid, filled with fluid, or both.
In an ultrasound examination, a wand or probe with a transducer sends the sound waves and records the echoing waves. When the transducer is pressed against the skin, it directs a stream of inaudible, high-frequency sound waves into the body. As the sound waves bounce off of internal organs, fluids and tissues, the sensitive microphone in the transducer records tiny changes in the sound's pitch and direction. These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor. These "live images" are temporarily recorded in the machine and one or more frames of the moving pictures are typically captured as still images.
Doppler ultrasound is a special application of ultrasound used for vascular exams. It measures the direction and speed of blood cells as they move through vessels. The movement of blood cells causes a change in pitch of the reflected sound waves called a "Doppler effect." A computer collects and processes the sounds and creates graphs and/or pictures that represent the flow of blood through the blood vessels.
Why would you need this exam?
Ultrasound examinations can help your doctor to diagnose a variety of conditions and to assess organ damage following an illness. Ultrasound can be used by your doctor to determine the causes of symptoms such as pain, infection and swelling. When ordering an ultrasound exam, your doctor might want to know more about many of your internal organs, such as:
- heart and blood vessels, including the abdominal aorta and its major branches
- liver
- gallbladder and bile ducts
- spleen
- pancreas
- kidneys
- bladder
- uterus, ovaries, and unborn child (fetus) in pregnant patients
- eyes
- thyroid and parathyroid glands
- scrotum
Ultrasound techniques are also used to:
- guide procedures such as needle biopsies , in which needles are used to extract sample cells from an abnormal area for laboratory testing
- image the breasts and to guide biopsy of breast cancer
- diagnose a variety of heart conditions and to assess damage after a heart attack or other illness
Doppler ultrasound images can help the physician to see and evaluate:
- blockages to blood flow such as clots
- narrowing of vessels which may be caused by plaque
- tumors and congenital malformation
With knowledge about the speed and volume of blood flow gained from a Doppler ultrasound image, the physician can often determine whether a patient is a good candidate for a procedure like angioplasty.
Pre-exam instructions for an ultrasound exam
Preparation for an ultrasound exam depends on the type of examination you will have. For some scans your doctor may instruct you not to eat or drink for as many as 12 hours before your appointment. For others you may be asked to drink up to four glasses of water two hours prior to your exam and avoid urinating so that your bladder is full when the scan begins. Special instructions based on the exam you need will be discussed with you when you call to make your appointment.
To schedule your ultrasound exam, please call us at (707) 525-4040. If you need to cancel, please call us 24 hours prior to your scheduled exam time.
The day of your exam
On the day of your exam, please arrive 15 minutes prior to your appointment time to check in and complete the necessary forms. Be sure to have your insurance information ready and available. Once you have registered, our ultrasound technologist will escort you to an exam room. You should wear comfortable, loose-fitting clothing for your ultrasound exam. You will need to remove all clothing and jewelry in the area to be examined. You may be asked to wear a gown during the procedure.
For most ultrasound exams, you will lie, face-up, on an examination table that can be tilted or moved. The ultrasound technologist will spread some warm gel on your skin and then press the transducer firmly against your body while moving it back and forth over the area to be studied.
A Doppler ultrasound exam is performed using the same transducer and general procedure. If a Doppler ultrasound study is performed, you may actually hear pulse-like sounds that change in pitch as the blood flow is monitored and measured. There may be varying degrees of discomfort from pressure as the transducer is pressed against the area being examined. If scanning is performed over an area of pain, you experience tenderness from the procedure.
After your exam
When the examination is complete you can dress and go to the bathroom. You may be asked to wait while the ultrasound images are reviewed. After an ultrasound exam, you should be able to resume your normal activities.
Ultrasound side-effects
There are no known harmful effects for standard diagnostic ultrasound exams.