Assessment of laryngeal function by digital subtraction laryngography.

The evaluation of vocal cord function can be problematic in the presence of oropharyngeal tumors, hypopharyngeal tumors, and supraglottic lesions and in noncompliant adult and pediatric patients. The use of computer image subtraction techniques coupled with digital fluoroscopy has inherent high-quality resolution that can provide an excellent image of vocal cord symmetry and movement. The use of air as the contrast medium provides the ability to measure the extent of vocal cord excursion as well as the extent of piriform sinus lesions. In addition, it is a noninvasive procedure that requires a minimal imaging exposure time, with the result that the patient undergoes minimal radiation exposure.