The value of the twinkling artefact for the diagnosis of sialolithiasis of the large salivary glands.

OBJECTIVE: The imaging of stones in the salivary glands and ducts poses a challenge, even to experienced ultrasound examiners. This study investigated whether the 'twinkling artefact', which occurs at internal calcific foci during Doppler ultrasound examinations, is useful for detecting salivary gland stones.

METHODS: In a model test, 20 salivary stones were analysed in vitro, via Doppler ultrasound, with regard to their representability and the triggering of the twinkling artefact. In a follow-up study, 28 patients with sialolithiasis and food-related large salivary gland swellings were examined, using both power and colour Doppler modes, with regard to the twinkling artefact. All ultrasound examinations were performed by an experienced examiner and retrospectively graded by two experienced sonographers.

RESULTS: All stones could reliably be detected using the twinkling artefact in the model test. Twenty-seven of 28 salivary stones (96 per cent) also showed twinkling in vivo, during patient assessment. The power Doppler mode showed a significantly higher intensity level of twinkling than the colour Doppler mode (p < 0.0001).

CONCLUSION: The twinkling artefact is a very reliable sign for the diagnosis of sialolithiasis. Power Doppler is superior to colour Doppler for detection of the twinkling artefact.