Navigating the Parotid Glands: Anatomy, Imaging Work-up and Next Steps

Imaging of the Major Salivary Glands in Rheumatic Disease

Salivary gland involvement is a common feature of rheumatologic disease. The authors review the anatomy of the major salivary glands and the uses of imaging modalities such as ultrasound, MRI, computed tomography, sialography, and scintigraphy in evaluating the major salivary glands in rheumatologic disease.

The anterior lobe of the parotid gland: a CT sialographic study

OBJECTIVES

To investigate the imaging and anatomic features of the anterior lobe (AL) of the superficial parotid gland (SPG).

METHODS

Computed tomographic sialography examinations were undertaken for 142 parotid glands in 77 patients. Whole computer tomography (CT) data were analyzed using multi-planar reformation and maximum intensity projection to generate sialographic CT images. The tributary ducts of the SPG were analyzed to classify the parotid morphology. Three-dimensional analyses were used to investigate the AL and its relationship with adjacent anatomic landmarks.

RESULTS

Four major types (I-IV) and 2 minor types (V-VI) of the AL and the superficial parotid gland were observed. Type I AL (83/142) was contiguous and not separated from the retromandibular parotid gland. Type II AL (16/142) was detached from the retromandibular parotid gland with 1-4 tributary ducts. Type III AL (12/142) showed a small isolated lobe above the Stensen duct around the anterior edge of the masseter. Type IV (28/142) showed the absence of the AL. Type V (3/142) shows the absence of the retromandibular parotid gland. Type VI (3/142) showed the presence of ectopic salivary gland beneath the Stensen duct anterior to the retromandibular parotid gland.

CONCLUSIONS

The AL gives rise to the morphological variations of the superficial parotid gland. AL also gives rise to the accessory parotid gland when it is detached from the retromandibular parotid gland.

Newly Discovered Parotid Lesion: What Next?

When a parotid lesion is discovered incidentally, it can be challenging for the radiologist to provide specific recommendations for the next steps. This article describes how the radiologist can play an active role in managing incidentally discovered parotid lesions. First, we explore the significance of parotid lesions. Next, the pertinent anatomy of the parotid space is presented to develop an appropriate differential diagnosis. Lastly, we discuss critical clinical and imaging characteristics the radiologist can use to provide specific recommendations.