The literature about bony defects in the semicircular canal system is highly inconsistent. Therefore, we analyzed a series of 700 high-resolution multislice CT examinations of the temporal bone for semicircular canal dehiscencies. An unselected group of ENT patients with different clinical symptoms and variable age was chosen. We found semicircular canal dehiscence in 9.6% of temporal bones, superior semicircular canal was affected mostly (8%), less common posterior semicircular canal (1.2%); only in 3 cases (0.4%), lateral semicircular canal showed dehiscence. In 60% of SSC dehiscence, we registered bilateral manifestation. The so-called "third mobile window" in semicircular canal dehiscence causes a great variety of clinical symptoms like vertigo, nystagmus, oscillopsies, hearing loss, tinnitus and autophonia. Comparison with anatomic studies shows that CT examination implies the risk of considerable overestimation; this fact emphasizes the important role of clinical and neurophysiological testing.

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Squamous cell carcinoma is the most common malignant neoplasm of the larynx. One of the most important influences on prognosis is the presence of metastases to the cervical lymph nodes. Accurate determination of lymph node involvement is therefore a prerequisite for individualized therapy in patients with squamous cell carcinoma of the larynx. Clinical palpation of the neck is not very accurate and the role of imaging techniques such as ultrasound, ultrasound-guided fine needle aspiration cytology, color Doppler ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography is being applied in order to improve upon the results of clinical investigation alone. According to our investigations and review of the literature, the accuracy of computed tomography scanning (84.9%) and magnetic resonance imaging (85%) was superior to palpation (69.7%) and ultrasound (72.7%). Ultrasound-guided fine needle aspiration cytology showed an accuracy of 89% and was in the same range with positron emission tomography (90.5%).