Ultrasound FAQs

Will I need to do anything to prepare for the test?

The preparations will depend on which type of ultrasound you are having. For ultrasounds of the abdominal area, including pregnancy ultrasounds and ultrasounds of the female reproductive system, you may need to fill up your bladder before the test. This involves drinking two to three glasses of water about an hour before the test, and not going to the bathroom. For other ultrasounds, you may need to adjust your diet or to fast (not eat or drink) for several hours before your test. Some types of ultrasounds require no preparation at all.

Your health care provider will let you know if you need to do anything to prepare for your ultrasound.

Ultrasound FAQs

What happens during an ultrasound?

A ultrasound usually includes the following steps:

  • You will lie on a table, exposing the area that’s being viewed.
  • A health care provider will spread a special gel on the skin over that area.
  • The provider will move a wand-like device, called a transducer, over the area.
  • The device sends sound waves into your body. The waves are so high pitched that you can’t hear them.
  • The waves are recorded and turned into images on a monitor.
  • You may be able to view the images as they are being made. This often happens during a pregnancy ultrasound, allowing you to look at your unborn baby.
  • After the test is over, the provider will wipe the gel off your body.
  • The test takes about 30 to 60 minutes to complete.

In some cases, a pregnancy ultrasound may be done by inserting the transducer into the vagina. This is most often done early in pregnancy.

Ultrasound FAQs

How do you prepare for an ultrasound?

Scans typically take between 20 and 60 minutes. When preparing for your exam, you should wear loose, comfortable clothing.  You may be asked to change into a gown for your exam.  Depending on your exam, you may have to avoid food or drink for a predetermined amount of time. For these exams, we try to schedule early morning appointments.  There are other exams that will require you to have a full bladder beforehand.  Your healthcare provider will tell you how you need to prepare for an ultrasound scan.

Ultrasound FAQs

How does ultrasound work?

Ultrasound uses high-frequency sound waves to produce a visual of internal organs and structures of the body. A transducer, or wand or probe, produces these sound waves that travel through tissues and fluids.

The sounds waves bounce back off denser tissues and structures; this is known as an echo. The denser the object is the greater the echo. The returning sounds waves produce the images in real-time, which means that ultrasound imaging can show the movement of the organs and blood flow.

Sonographers perform the scan while a specialist — such as a radiologist or cardiologist — examines and interprets the images.

Ultrasound FAQs

What is ultrasound therapy and can it treat rheumatoid arthritis?

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease which primarily causes chronic pain, inflammation, swelling and stiffness. Currently, treatment involves the use of medications to alleviate symptoms, some of which include corticosteroids, over-the-counter pain relievers, and immunosuppressants, amongst others. The primary aim is to alleviate symptoms, as well as slow down progression of the condition.

Alternative treatment measures are something that medical scientists and researchers have been investigating for some time. Ultrasound therapy is one line of research that has cropped up as a potential means to effectively treat RA.

Research has looked into how high-frequency sound waves, which bounce off muscles, tissues and organs may be able to treat RA by relieving pain and inflammation, as well as promote the healing of bodily tissues affected by the disease.

Ultrasound therapy is not entirely a new concept and uses technology to better target painful areas. It was documented as a possible treatment option around the 1920s and early 1930s when it was used to alleviate symptoms of sciatica (a radiating pain that occurs due to pressure on the sciatic nerve, which runs from the lower back and down the legs).

It is known that an ultrasound procedure can slightly heat up tissues in the body. By heating deep tissues, experts have been able to identify possible benefits of using ultrasound in a therapeutic way (1).

Some ways this can potentially be achieved include:

  • Helping to increase or improve circulation in the body
  • Promote tissue and bone healing (reducing the risk of bone erosion and the development of deformities)
  • Encourage an ‘internal massage’ effect
  • Alleviating inflammation and pain, most notably when applied to the hands (studies have shown that this can improve grip strength, wrist flexibility, reduce swelling of joints and alleviate morning stiffness).

Many doctors and rehabilitation therapists already use ultrasound technology (or therapy) to treat and manage RA symptoms. Ultrasound imaging is also very useful for monitoring and tracking the progression of both the disease (detecting inflammation in the joints) and effectiveness of treatment.

For the most part, ultrasound therapy has not been shown to cause long-term side-effects and complications, and although treatment links have been established in numerous studies, more comprehensive high-quality investigations may still be required before ultrasound therapy can form part of a standard treatment plan.

Ultrasound FAQs

Are multiple prenatal ultrasounds safe for an unborn baby?

To date, it has not been proven than multiple ultrasound scans during a woman’s pregnancy causes any long-term harm to a developing foetus (unborn baby). Many studies have deduced that multiple scans are unlikely to cause any undesirable side-effects.

More than a decade ago, concerns about multiple prenatal ultrasounds flagged potentially stunted growth in new-born babies whose mothers underwent regular ultrasounds in comparison to women who had one scan during their pregnancy. Since then studies have dispelled this notion. No significant or directly linked long-term problems with growth and development (including speech, language, behaviour and other neurological developments) have been noted since.

Ultrasound FAQs

What is an ultrasound?

An ultrasound scan uses sophisticated equipment to send sound waves into the body and captures the returning data to create images that are looked at by the sonographer and interpreted by a radiologist.

Ultrasound medical device for diagnostics
Ultrasound FAQs

What are the limitations of General Ultrasound Imaging?

Ultrasound waves are disrupted by air or gas. Therefore, ultrasound is not an ideal imaging technique for the air-filled bowel or organs obscured by the bowel. Ultrasound is not as useful for imaging air-filled lungs, but it may be used to detect fluid around or within the lungs. Similarly, ultrasound cannot penetrate bone, but may be used for imaging bone fractures or for infection surrounding a bone.

Large patients are more difficult to image by ultrasound because greater amounts of tissue weaken the sound waves as they pass deeper into the body and need to return to the transducer for analysis.

Ultrasound has difficulty penetrating bone and, therefore, can only see the outer surface of bony structures and not what lies within (except in infants who have more cartilage in their skeletons than older children or adults). Doctors typically use other imaging modalities such as MRI to visualize the internal structure of bones or certain joints.

Ultrasound FAQs

What are the benefits vs. risks?


  • Most ultrasound scanning is noninvasive (no needles or injections).
  • Occasionally, an ultrasound exam may be temporarily uncomfortable, but it should not be painful.
  • Ultrasound is widely available, easy to use, and less expensive than most other imaging methods.
  • Ultrasound imaging is extremely safe and does not use radiation.
  • Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
  • Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn babies.
  • Ultrasound provides real-time imaging. This makes it a good tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration.


  • Standard diagnostic ultrasound has no known harmful effects on humans.
Ultrasound FAQs

Who interprets the results and how do I get them?

A radiologist, a doctor trained to supervise and interpret radiology exams, will analyze the images. The radiologist will send a signed report to the doctor who requested the exam. Your doctor will then share the results with you. In some cases, the radiologist may discuss results with you after the exam.

You may need a follow-up exam. If so, your doctor will explain why. Sometimes a follow-up exam further evaluates a potential issue with more views or a special imaging technique. It may also see if there has been any change in an issue over time. Follow-up exams are often the best way to see if treatment is working or if a problem needs attention.