A foreign body is any material that enters the body from the outside and is not naturally present. Ultrasound is an excellent tool for detecting and localizing foreign bodies in soft tissues, particularly those that are not visible on X-ray, such as wood splinters, thorns, and plastic fragments. On ultrasound, most foreign bodies appear as hyperechoic structures, often with posterior acoustic shadowing or a surrounding hypoechoic halo of inflammation. Real-time ultrasound guidance can then be used to assist with surgical removal of the foreign body. Ultrasound is also used to identify retained surgical materials, including sponges and other objects accidentally left inside the body during surgery.
Sonography Term