Imaging Studies

The routine use of imaging in small well-defined masses of the superficial lobe of the parotid gland is probably not warranted, because imaging in such instances rarely alters the planned management. However, tumors presenting with clinical findings suggestive of malignancy, tumors arising from the deep lobe of the parotid gland, or tumors extending to the parapharyngeal space are better evaluated with high-resolution imaging. Computed tomography (CT) and magnetic resonance imaging (MRI) give a better understanding of the location and extent of the tumor, its relation to major neurovascular structures, per-ineural spread, and skull base invasion. Conventional radiography and sialography are rarely used because they provide little useful information. Nuclear imaging using technetium-99m pertechnetate is helpful only with oncocytic and Warthin's tumors.10 Because aspiration needle biopsy can provide better information, nuclear imaging is rarely obtained. High-resolution ultrasound is useful in the hands of experienced radiologists and may detect calculi, abscesses, and cysts; it has been reported to assess up to 90% of benign versus malignant tumors correctly.11 Imaging modality of choice in evaluating parotid masses remains somewhat controversial among clinicians. Most of this controversy represents either personal or institutional bias, and there is a paucity of published data comparing the merits of different imaging modalities in the evaluation of parotid tumors. Some of these data are outlined herein.

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