Radiological appearances of parotid duct calculi.

A total of 42 patients presenting with recurrent unilateral parotid gland swelling was studied. Plain radiology of 38 patients with proved calculi showed that the lateral view is valueless. The anteroposterior view was positive in 58 per cent, and when coupled with an intrabuccal view 71 per cent of the calculi were radio-opaque. The overwhelming majority of calculi were visible as filling defects on sialography, while in 4 patients an area of narrowing with dilatation of the parotid duct proximal to it represented the site of the calculus. In the remaining 4 patients with the latter sign, repeat sialography showed normal appearances in 2, suggesting that the calculi had passed.