Ultrasound
What is ultrasound imaging?
Ultrasound imaging, or ultrasonography, is a procedure that uses high frequency sound waves to develop images of internal structures and tissues. In most ultrasound procedures, a small, hand-held device called a transducer is used to scan the area of the body being examined. The transducer functions as both a generator of sound and a receiver. When it is placed on the skin, it directs sound waves into the body. As the sound waves echo off the body's tissues and fluids, the transducer records the reflected waves. The echoes are instantly displayed on a screen.
How is ultrasound used in medicine?
What should I expect?
How long will it take?
How do I prepare?
Locations
How is ultrasound used in medicine?
Ultrasound examinations are performed to help in the diagnosis of a wide range of diseases and conditions. Because an ultrasound shows motion, it is very useful for studying the flow of blood through veins, arteries and the heart. During pregnancy, ultrasounds are done to evaluate the development and movement of the fetus.
An ultrasound examination can be used to examine many parts of the body, including the abdomen, heart, kidneys and liver. Ultrasound imaging is also used to diagnose prostate abnormalities and gallstones, and to reveal the shape, texture and composition of various tumours or cysts.
What will happen during my ultrasound exam?
During a typical ultrasound procedure, you will be positioned on an exam table. The technologist or physician conducting the procedure will then spread a clear gel over the area of your body that is being examined. The gel aids in the transmission of sound waves and allows the transducer to pass smoothly over the area. Once the gel is applied, the technologist will press the transducer firmly against your skin and sweep the device slowly over the body part in question. An ultrasound image will be immediately visible on a nearby screen. Throughout the exam, images on the screen will be recorded so that a radiologist can review them.
Unlike an X-ray, an ultrasound emits no radiation, and there are no known side effects or risks associated with the procedure. An ultrasound is generally non-invasive. However, there should always be a valid medical reason to perform an ultrasound examination.
How long will the ultrasound exam take?
An ultrasound exam usually takes about 30 to 60 minutes, depending on the body part under study.
How do I prepare for my ultrasound exam?
Many ultrasound exams require no special preparation, while others have unique requirements. If any preparations are necessary, you will be informed ahead of time. Below is a list of ultrasound exams that require some preparation prior to the exam:
Urinary Bladder or Pelvis or Pregnancy Under 30 Weeks
This examination must be done with a very full urinary bladder. Ninety minutes before your appointment, empty the bladder and then drink five 8-ounce glasses of water within one-half hour. If your bladder is not full, your examination may need to be rescheduled. For pre-menopausal women, the optimal timing for pelvic ultrasound is in the week after the end of menstrual flow. This does not apply to urgent examinations or examinations during pregnancy.
Pregnancy 30 Weeks and Over
Do not smoke for two hours before your exam. Have a large snack and three glasses of water one hour before examination.
Biophysical Profile
This examination is ordinarily requested only after 30 weeks of pregnancy. Do not smoke for two hours before your exam. Have a large snack and three glasses of water one hour before examination.
Abdomen, Liver, Pancreas, Aorta, Kidneys or Gallbladder
Do not eat or drink for six hours prior to the examination. If you are also having small bowel or colon examination, fast from 10:00 p.m. the evening before your exam.
Combination Examination of the Urinary Bladder or Pelvis Together with Abdomen
Do not eat or drink for six hours prior to the examination except: 90 minutes before your appointment time, empty the bladder and then drink five 8-ounce glasses of water within one-half hour. If your bladder is not full, your examination may need to be rescheduled.
If your ultrasound exam will be a combination of any of those listed above, be sure to follow the instructions laid out for each of the relevant procedures.
