Ultrasound is an imaging technique that uses sound waves. Special crystals in a transducer emit these high-frequency sound waves that can penetrate the body. These sound waves are then reflected by the body and the various tissues (= echo) and collected by the same transducer. Since each type of tissue reflects these sound waves in a different way, the computer that converts the reflected signals can make an image of them.

Gel is placed between the transducer and the skin for better conduction of the sound waves. An ultrasound is a painless and harmless examination. Ultrasound is also used in a biopsy when a piece of tissue is taken with a needle to examine under the microscope. The ultrasound is then used to guide the needle in order to pinpoint where the biopsy is to be taken very accurately. The possibilities and accuracy of ultrasound are becoming increasingly extensive, and ultrasound is a frequently applied examination in the diagnosis of liver abnormalities.

Below is an ultrasound of a normal, healthy liver.

Ultrasound of the liver and gallbladder. The main bile duct (CBD) and portal vein (MPV) are also visible.