What is it?
An ultrasound scan is a test that uses high frequency sound waves to create an image of internal organs such as the liver and kidneys. As sound waves are used rather than x-rays the procedure is very safe. Ultrasound scans are commonly used during pregnancy to produce images of the baby in the womb.
Ultrasound is useful to examine the abdominal organs such as the liver, gallbladder and kidneys and other superficial structures such as the thyroid gland. It can also be used to assess the blood flow through arteries and veins and measure any dilated arteries such as the aorta or narrowings such as in the arteries supplying the brain. In infants, the brain can be examined by ultrasound for as long as the soft spot (fontanelle) remains open. Ultrasound of the skin or breast is very useful to examine the nature of any lumps.
Ultrasound is very good to assess the superficial structures which make up the joints of the body and have the advantage of being able to create an image with the structures being moved. Ultrasound is also used to direct injections for muskuloskeletal problems or to biopsy lesions within organs such as the liver or breasts.
How is the scan done?
The scan will be performed by a consultant radiologist and usually takes between 10 and 30 minutes. The scan is usually performed with the patient lying on their back and a probe is moved over the skin overlying the area of interest. A water gel will be used to ensure good contact between the probe and skin. Before some types of ultrasound scan, you may be asked to follow some instructions before the procedure; before a scan of the bladder or female pelvis to drink plenty and not go to the toilet until after the test; before a scan of the gallbladder or liver to avoid eating for several hours before the scan. Some organs of the body such as the prostate gland, ovaries and uterus are best examined with an internal examination when the probe is placed in the rectum or vagina.
Sometimes contrast can be injected at the time of scan which is comprised of millions of microscopic bubbles which can assess the blood flow to organs and tumours.
Ultrasound of the liver
Ultrasound of the thyroid gland