*3.1. Visualization of Sublingual Gland Ducts by MR Sialography*

Extraglandular portions of the typical sublingual gland ducts on MR sialography could be identified as many bright, homogeneous, ascending linear structures in continuity with the sublingual glands (Figure 1)**.** The MR sialographic 3D reconstruction images of the respective angles were more easily visualized when the angle was determined manually using the mouse accompanying the MRI system. Both sublingual glands and sublingual gland ducts could be accurately visualized in 16 of the 20 adult volunteers, 12 of the 19 elderly volunteers, and 4 of the 7 patients, but only the sublingual glands were visualized in 2 adult volunteers, 4 elderly volunteers, and 1 patient (Table 3).

**Figure 1.** MR sialography of sublingual gland ducts. Extraglandular portions of the typical sublingual gland ducts in MR sialography ((**A**): overall image, (**B**): enlarged image of the sublingual gland area) can be identified as many bright, homogeneous, ascending linear structures (arrows) in continuity with the sublingual glands (arrowheads).

**Table 3.** Summary of visualization of sublingual gland ducts by MR sialography.

