152 THE LARYNX, BRONCHI AND OESOPHAGUS
exophytic supraglottic tumour which obscures the vocal cords on mirror
examination. It is also of importance in identifying the site and extent of a
tracheal stenosis. The use of the polytome has made this a procedure of high
Fig. 71. Tomograph to show glottic carcinoma of larynx.
Fig. 72. Laryngogram.
3. Laryngography (Fig. 72). Laryngography is a relatively new procedure
which has added a new and valuable dimension to the investigation of
laryngeal disease. It is done by drying the larynx by giving the patient an
injection of atropine, anaesthetizing it by a superior laryngeal nerve block, and
running a little radio-opaque dye into the larynx by means of a catheter
passed through one nostril into the pharynx. Once the dye is in the larynx the