Due to underlying Sjogren’s syndrome, there is extreme fatty replacement of both submandibular (shown on A) and the parotid (shown on B) glands. However, the right submandibular gland is enlarged compared to the left, has internal edema and increased attenuation, substantial surrounding stranding as well as infiltrative edema extending to the adjacent tissues. Notice how on image A, the edema extends to the right aspect of the oropharynx and results in effacement of the right vallecula compared to the left.
On image B, you can see bilateral distal submandibular duct stones. There are quite a few more stones shown below:
In the above images, you can see several additional right submandibular duct stones. On image B and coronal image C, you can see that the right submandibular duct is dilated and has mucosal hyperenhancement (seen best on coronal image C).
These constellation of finding are consistent with right submandibular sialadenitis due to sialolithiasis.