Swelling at the angle of the mandible: Imaging of the pediatric parotid gland and periparotid region

The pediatric parotid gland and periparotid region are subject to a variety of lesions and are most often evaluated with ultrasonography (US), contras t material-enhanced computed tomography (CT), and magnetic resonance (MR) i maging. US may be used to assess the size of the parotid gland, distinguish diffuse from focal disease, assess vascularity and adjacent vascular struc tures, distinguish cystic from solid lesions, and guide fine-needle aspirat ion. However, further evaluation with CT or MR imaging may be needed to bet ter define the nature and extent of disease. CT is the imaging modality of choice for most pediatric parotid disease (including acute inflammation, ab scess, calculi, and major salivary duct obstruction) and most solid masses and may obviate sedation. However, a mass associated with facial nerve symp toms should be evaluated with MR imaging because it is the only modality th at can consistently demonstrate the facial nerve. Findings at US, CT, and M R imaging allow localization of parotid lesions and may suggest a specific cause. Clinical information, familiarity with normal parotid anatomy at var ious stages of its development, and knowledge of the imaging characteristic s of parotid and periparotid lesions are essential for appropriate radiolog ic evaluation. This information can be used to guide therapy and plan a sur gical approach.