The role of ultrasound and computed tomography in the evaluation of parotid masses.

A prospective sonographic study of 40 patients with symptomatic parotid masses detected all of their 48 lesions (sensitivity 100%). Computed tomography (CT) detected 47 lesions (sensitivity 97.5%). Ultrasound correctly characterized all benign tumours and inflammatory lesions and four out of five malignant tumours. Deep compartment involvement was accurately delineated in 10 (25%) patients but in two patients the extraparotid tumour origin could only be detected by CT. Ultrasound is a sensitive, non-invasive investigation of parotid masses. Computed tomography (CT) or magnetic resonance should be reserved for lesions that involve the deep compartment of the gland and cannot be separated from the parapharyngeal space or skull base.