FIG 5. 36-year-old patient suspected to have sialolithiasis.

A, Lateral digital subtraction sialogram shows a slightly dilated Wharton duct (arrow) and sialectasis in secondary duct branches (arrowhead). No filling defect in the main duct is seen.

B, Transverse MR sialogram shows a filling defect near the orifice of the left Wharton duct (arrow). Note also the markedly dilated left Wharton duct compared with the right side. Patient underwent surgery, and a sialith was confirmed. The false-negative digital subtraction sialographic result may be due to dental hardware or to the fact that the sialographic catheter already passed the distal stone.