Sonographic examination of sialolithiasis.

Ultrasound examination for sialolithiasis was carried out in ten cases, and the findings were compared with those from sialography. Salivary stones were recognized as high-level reverberation echoes accompanied by posterior acoustic shadows in eight cases, whereas in the remaining two they appeared only as hyperechoic masses. In a case of sialolithiasis of the parotid gland that was difficult to detect by simple radiographic examination, a salivary stone was detected by both sialographic and ultrasonographic examination. Clearly separated salivary stones were also easily detected in each case by the ultrasonographic method, but multiple, gathered calculi were not precisely detected. The smallest sialolith that could be detected was approximately 2 x 3 mm in size. The rate of detection of salivary stones by using the ultrasonographic method was as high as that from using sialography. Because the examination is simple and noninvasive, its use to evaluate sialolithiasis is probably indicated more frequently, especially when there is acute infection in the gland.