In diagnosis and staging of laryngeal pathology, CT has been used as a method of choice, and a recent study showed that MR is mors sensitive and specific than CT. High-resolution ultrasound is not a routine examination in laryngeal disease,
however,
several studies using ultrasound insisted the usefulness of the ultrasound in evaluation of laryngeal disease. We analized dynamic sonographic findings of the vocal cords in 27 healthy volunteers. Length of the true vocal cords, distance of rima
glottids, distance between two false cords were measured in quiet breathing, deep inspiration, breath holding, and Valsalva manuever state. We also evaluated change of the vocal cord shape during phonation. True vocal cords are hypoechoic, false
vocal
cords are hyperechoic, and vocal ligaments are hyperechoic in free margin of the true cords. The thyroid cartilage shows hyperechoic cortical margin with variable inner echogenicity. The arytenoid cartilages are identified as echogenic dots.
During
quiet breathing, position of the true cords is intermediate between deep inspiration and breath holding. Vocal cords are adducted during breath holidng, and abducted in deep inspiration state. Movement of the vocal cords is always symmetrical. We
concluded that ultrasound is a potentially useful technique for examination of the vocal cords. Comparative studies between sonography and CT and MR is necessary to determine the role of sonography.
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