MR anatomy of salivary glands in the dog

This retrospective analysis documented the magnetic resonance imaging (MRI) appearance of normal salivary glands based on 101 studies in dogs with no detectable disease in the splanchnocranium. Surface, signal intensity, homogeneity, structure, symmetry and the relationship of glands to surrounding tissues were noted, and gland topography was assessed with E12 plastinated embedded sections. Signal intensity of salivary glands was isointense (7-40%) to hyperintense (60-90%) to muscle tissue on T1- and hyperintense on T2-weighted images. Salivary glands had an increased T1 signal after contrast medium was applied. Salivary gland structure appeared homogeneous in mandibular and major sublingual glands and heterogeneous in zygomatic and parotid glands. Consistent landmarks were the external auditory canal for parotid glands, the digastric muscle for mandibular and major sublingual glands, and the pterygopalatine fossa for zygomatic glands. The minor sublingual and ventral buccal glands could not be localized with low-field MRI.