Ultrasound scanning refers to exposing body parts to sound waves that produce images of internal body parts. These high-frequency waves of sound are considered a safe method of medical imaging because they do not involve the use of ionizing radiation the way x-rays do. In addition, ultrasound scanning images are performed in real time, which allows the visualization of internal organs while they are moving. The ultrasound scan also is effective in capturing images of blood flowing through the vessels.
Typically, ultrasound scanning can include three-dimensional imaging and four-dimensional imaging, which refers to three-dimensional ultrasound in motion. Doppler ultrasound may be included in an ultrasound scan, which refers to a technique that evaluates the flow of blood in the major arteries of the neck, limbs, and abdomen. This type of ultrasound can be effective in diagnosing blockages in the carotid arteries and legs. This painless method of medical imaging can offer immediate results without side effects or adverse reactions.
Generally, ultrasound scanning is based on the bouncing back, or echoing, as a sound wave hits an object. During an ultrasound scan, an instrument called a transducer is pressed to the skin where it directs pulses of sound waves through the body. The skin is prepared to accept the transducer with a clear gel that is applied to the specific area that is being studied. This gel helps make a secure contact by eliminating pockets of air between the skin and the transducer. The technician presses the transducer against the skin, while sweeping the areas of interest.
Benefits of ultrasound scanning include the non-invasiveness of the test and the lack of pain that it involves. In addition, ultrasound scanning is generally less expensive than other methods of medical imaging. Because the ultrasound is considered very safe, it is the preferred method of diagnostic imaging in pregnant women and unborn babies. Although ultrasound scanning is considered reliable and safe, it does have limitations. Sometimes, in large patients, images may be more difficult to acquire. This happens because more tissue can weaken sound waves when they pass into the body. As sound waves weaken, image quality deteriorates.
Another downside of ultrasound scanning is that it is ineffective in visualizing the internal structure of joints and bones. Typically, when images are needed to visualize the internal structures of bones, magnetic resonance imaging or MRI is usually used. In addition, the ultrasound scan may not be ideal for imaging the bowel. Generally, when needing diagnostic images of the bowel, barium examinations, CT scans and MRI examinations are the general methods of choice.
