Ultrasound
An ultrasound scan builds up pictures of organs and areas inside the body using sound waves. These sound waves have a frequency beyond human hearing. An ultrasound scan is often used during pregnancy to obtain pictures of a baby in the womb.
An ultrasound scan does not use X-rays and is entirely safe. The ultrasound waves are delivered by a small handheld transducer similar to a microphone. The transducer is moved over the surface of the skin and it picks up the sound waves as they return from various organs within the body. A computer, which is linked to the transducer, turns the sound waves into pictures that are viewed on a monitor. Images are stored and then interpreted by trained specialists.
Ultrasound scans can be used to help doctors to make a diagnosis or assess the effects of treatment. Your doctor will recommend an ultrasound scan based on the type of cancer you have and the information needed. Ultrasound can also be used to detect blood flow and whether there is any narrowing or blockage of blood vessels.
There are no known risks with ultrasound and it is considered to be very safe. The scan does not hurt but you will feel a gentle pressure of the sensor over the skin. If you are to have an internal scan any sensations you may feel will be explained to you. Most scans take about half an hour.
Types of ultrasound scan
There are several types of ultrasound scans and the procedure for your scan will be explained to you before your appointment. Sometimes, doctors need to put a special ultrasound transducer inside the body to get a clearer picture. Special transducers have been developed to 'look inside' the body.
Guided biopsy / fine needle aspirate (FNA)
Other procedures, such as biopsies, may be performed at the same time as the ultrasound. If the sonographer or doctor performing the scan notices an area which looks unusual, in the breast or liver for example, they may want to take a biopsy or fine needle aspirate (FNA) – a sample of cells or tissue – from that area. With some biopsies, for example a liver biopsy, you may need to stay in hospital overnight.
Contrast enhanced ultrasound
Your sonographer or doctor may wish to characterise a lesion further by injecting fluid (ultrasound contrast) which is often given into a vein in your arm or hand. The fluid is not radioactive. You will be asked about allergies, tablets and heart conditions to assess your suitability to have the injection.
After your ultrasound scan
As soon as the scan is complete you may get ready to go home or back to your hospital ward. The gel will be removed before you get dressed. You may go to the toilet and eat and drink as usual.
There are no side effects to the ultrasound scan and it is safe to drive or return to work after your scan.