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Ultrasound

​Ultrasound is high-frequency sound that travels through skin and fluid, but it bounces back, or echoes, off denser surfaces; thus creating an image.

Ultrasound
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An ultrasound scan uses high frequency sound waves to examine various structures in the body including large organs and blood vessels. High frequency sound waves are transmitted into the body when a scanning probe is placed on the skin which enables the ultrasound machine to produce live or real-time images of your internal organs.

Most people associate ultrasound scans with pregnancy. These scans can provide an expectant mother with the first view of her unborn child. However, the test has many other uses.

Your doctor may order an ultrasound if you’re having pain, swelling, or other symptoms that require an internal view of your organs. 

An ultrasound can provide a view of the:
Bladder, prostate, gallbladder, kidneys, liver, ovaries, pancreas, spleen, thyroid, testes, uterus, blood vessels, muscle.

An ultrasound radiographer, called a sonographer, will apply a special lubricating gel to your skin. This prevents friction so they can glide the ultrasound transducer on your skin. The transducer has a similar appearance to a wand. The gel also helps transmit the sound waves, which then forms a picture that can be interpreted by the doctor.

Depending on the area being examined, you may need to change positions so the technician can have better access.

As with most radiological procedures, there may be preparations that will be required to be done by you. Below are some preparations needed to ensure a successful and smooth ultrasound scan appoinment.

Ultrasound Abdomen / Hepatobiliary System (HBS) / Doppler Aorta / Hepatic Vessels / Transplant Liver / Doppler Renal arteries or veins / Liver Doppler / Renal Doppler
- FAST according to the duration below:
  DO NOT eat 6 hours prior to the scan.
- Sips of plain water allowed.
- DO NOT smoke on the day of examination.

Abdomen & Pelvis
- FAST according to the duration below:
  DO NOT eat 6 hours prior to the scan.
- DO NOT smoke on the day of examination.
- Drink at least 4 cups of plain water (1 hour before scan) to keep your bladder FULL. (Omit this instruction if you are on fluid restriction.)
- Do not empty bladder till scan is completed or as instructed by sonographer.

Kidney, Bladder, Pelvis, Prostate, Urinary Bladder
- No fasting
- Drink at least 4 cups of plain water (1 hour before scan) to keep your bladder FULL. (Omit this instruction if you are on fluid restriction.)
- Do not empty bladder till scan is completed or as instructed by sonographer.
- Transvaginal scan may be performed if neccessary, but consent will be seeked before proceeding with the scan

Other scans not indicated above
No fasting preparation
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​Before the scan
You will be asked to lie down on the examination couch and the area of the body to be examined will be uncovered. A thick water base gel will be applied over the area under examination. 

During the scan 
  • ​Our trained sonographer will place the ultrasound probe over the gel and will move the probe over the area under examination. 
  • Instructions (such as turning to one side or holding your breath for a few seconds) will be given during the scan so that the sonographer can achieve the clearest images.
  • Throughout the procedure, the room lights will be dimmed in order for the sonographer to visualize the images on the monitor properly.
  • A typical ultrasound exam will take approximately 30 minutes to two hours to complete, depending on types of scans.
After the scan
Upon completion of examination, the gel is wiped off and you will be able to leave the department.
Ultrasound is usually painless. However, you may experience mild discomfort when the sonographer is guiding the ultrasound probe over your body, especially if you are required to have a full bladder, or inserts it into your body.

  • There is typically no special care required. You will be able to return to normal activities immediately after Ultrasound scan.
  • There is generally no special post-scan care for Ultrasound and you should be able to resume your usual diet and activities after the scan unless there are other procedure(s). 
  • ​Our radiologists will read and report your scan images. A report will then be sent to your referring clinician electronically, who will then discuss the scan results with you at your next appointment in the clinic.
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Is Ultrasound safe?
Ultrasound is one of the safest imaging techniques as it does not involve radiation. It is always the first imaging technique to be considered for pregnant women.

COVID-19 Vaccines and Ultrasound Breast Scan:
Some people may experience enlarged/swollen lymph nodes after the Covid-19 vaccination, and this may affect the interpretation of the ultrasound results. While not everyone will experience post-vaccine symptoms, women are encouraged to schedule their ultrasound appointment before the first dose of the Covid-19 vaccination or at least four to six weeks after the final vaccine dose.

Discuss with your doctor if you are to go for an ultrasound procedure soon after you get the vaccine. Your doctor will be able to advise on the situation. We advise patients not to delay ultrasound without seeking doctor’s advice.
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Contributed by Department of Radiology​.​​