The labial salivary gland is a site of occurrence of tumors and cysts, and it serves as the biopsy site for the diagnosis of Sjögren syndrome. However, its imaging features have not been well understood. Here we attempted to depict the labial gland by high-resolution MR imaging.
The labial glands from 89 patients without Sjögren syndrome, 14 patients with Sjögren syndrome, and 3 patients with tumor or cyst of the lips were imaged by using a 1.5T MR imager with a 47- or 110-mm surface coil.
The upper and lower labial glands consisted of 1-3 layers of gland clusters, each of which had high signal intensity on T1-weighted and fat-suppressed T2-weighted images and was readily enhanced after gadolinium injection. The posterior parts of the glands were thicker than the anterior parts. The gland areas in the lower lips (186 +/- 64 mm(2) in women and 192 +/- 68 mm(2) in men) were greater than those in the upper lips (140 +/- 46 mm(2) in women and 162 +/- 66 mm(2) in men). We did not find any significant age-related changes or sex differences in the gland area. The labial gland areas were smaller in the patients with Sjögren syndrome than in patients without Sjögren syndrome, though the difference was significant only in the upper lips (104 +/- 53 mm(2)).
This is the first report describing imaging features of the labial salivary glands. High-resolution MR imaging can readily delineate the labial glands.