In many cases of radiolucent foreign bodies in the airway of infants, diagnosis is difficult. The diagnostic method has been mainly to detect Holzknecht's sign through conventional radiography. However, it has been difficult to obtain highly reliable information for detecting foreign bodies or determining the site of the foreign bodies by this diagnostic method alone.
The recently developed digital radiography utilizes digital signals which are converted from X-ray energy to get clear images. The image processor which consists of a high speed computer, mathematically integrates the signals to visualize the spacific site. Digital fluorography, in particular, is widely applied clinically in vascular radiography in the form of digital subtraction angiography. The authors applied digital fluorography to two infants cases of radiolucent foreign bodies (peanuts) in the airway. The results suggested that the method could be usefully applied to diagnose foreign bodies in the airway and to detect the sites of the foreign bodies.
