marker is over the foreign body and the skin should be marked to identify this optimal incision site After appropriate anesthetic injection and incision, image the foreign body in the long axis and use forceps or hemostats to grasp the object under ultrasound guidance FIGURE 131.34 Abscess Pitfalls Bone and joint surfaces appear hyperechoic with shadowing, and can be confused with foreign bodies if one is not familiar with the local anatomy Scar tissue can also appear hyperechoic and must be differentiated from foreign bodies Wooden foreign bodies may become less echogenic over time, making them more difficult to see Finally, using ultrasound dynamically to remove a foreign body is technically challenging It requires a moderate amount of ultrasound experience and dexterity The novice user may have greater success in identifying the foreign body statically in multiple planes, marking the site and attempting removal in standard fashion OTHER USES OF ULTRASOUND There are other uses of sonography that are beyond the scope of this chapter We touch upon them briefly here to introduce the concepts The interested reader should consult a textbook of ultrasonography