Potentials and limitations of color Doppler sonography in the head and neck region

Sonography has provided an important addition to the tools available for th e diagnosis of the soft tissues in the head and neck region. The ENT surgeo n himself is able to examine pathological formations by this quick, non-inv asive and, last but not least, less expensive method. Due to the high resol ution of the procedure the chance of detecting even small changes is increa sed and the exactness of diagnosis of pathological lymph nodes of the neck has been significantly improved compared to palpation alone. Ultrasound has replaced the sialographic procedures in the field of diagnostic evaluation of salivary gland disease in the daily practice except for special indicat ions. After inauguration of color Doppler sonography non-invasive evaluatio n of vascular stenosis of the large cervical vessels concerning their hemod ynamic effects has become possible. This issue is important for the differe ntial dignosis of otoneurological diseases such as sudden hearing loss, ver tigo and tinnitus. Additionally, the extent of perfusion of space-occupying lesions can be easily examined, and therefore the risk of mass bleeding ca n be preoperatively assessed by this method without ha rm to the patient. E specially carotid body tumors may be diagnosed with high accuracy by the ev idence of significant diffuse perfusion of the lesion. In several studies t he specificity of the assessment of cervical lymph node disease could be in creased by examination of resistance indices. However, other authors have s hown inconsistent results in differentiation of benign and malignant lumps; therefore, final judgment does not seem to be possible yet. Use of echo-co ntrast agents to enhance the ultrasound signal seems to be a promising appr oach for future developments in color Doppler imaging.