Ultrasound involves the use of high-frequency sound waves to create images of organs and structures within the body. An ultrasound probe covered with a coupling gel is placed on the skin surface of the organs being investigated. The probe send out a high frequency sound wave which is attenuated and reflected to different degrees by different tissues and interfaces within the body. The same probe then receives the reflected sound waves and uses this information to produce a real time image on a monitor. This image is then interpreted by the attending radiologist or sonographer.
Ultrasound has great value in examining soft tissues, especially within the abdomen and pelvis, but also the tendons and ligaments around joints. Doppler ultrasound is a specific technique which employs the change in frequency of reflected sound waves to determine flow characteristics within blood vessels. This is used in both arterial and venous imaging studies. Ultrasound is limited by air and bone, through which ultrasound images cannot be obtained. Patients are often required to remain nil per mouth before the study to limit stomach gas or to drink lots of fluids, filling the bladder and displacing gas filled bowel loops away from the pelvis. Unlike with an x-ray or CT scan, there is no ionizing radiation exposure with this test.
- Obstetric - 1st trimester
- Other soft tissues
See www.radiologyinfo.org for more information on radiological studies.