An ultrasound scan uses high-frequency sound waves to create images of the inside of the body. It is suitable for use during pregnancy.
Ultrasound scans, or sonography, are safe because they use sound waves or echoes to make an image, instead of radiation.Ultrasound scans are used to evaluate fetal development, and they can detect problems in the liver, heart, kidney, or abdomen.
The person who performs an ultrasound scan is called a sonographer, but the images are interpreted by radiologists, cardiologists, or other specialists. The sonographer usually holds a transducer, a hand-held device, like a wand, which is placed on the patient's skin.
How ultrasound scans work
A small device called an ultrasound probe is used, which gives off high-frequency sound waves. You can't hear these sound waves, but when they bounce off different parts of the body, they create "echoes" that are picked up by the probe and turned into a moving image. This image is displayed on a monitor while the scan is carried out. It will travel straight through the gallbladder if there are no gallstones, but if there are stones, it will bounce back from them. The denser the object the ultrasound hits, the more of the ultrasound bounces back. This bouncing back, or echo, gives the ultrasound image its features. Varying shades of gray reflect different densities.
Preparing for an ultrasound scan
Before having some types of ultrasound scan, you may be asked to follow certain instructions to help improve the quality of the images produced. For example, you may be advised to: