Retention of lipiodol after parotid gland sialography

There is limited information about the retention of lipiodol in the parotid gland after parotid gland sialography. This study assesses the prevalence of lipiodol retention after parotid sialography and determines if retention of lipiodol is related to the sialography technique or the underlying salivary gland pathology. Using the electronic hospital database (1996–2006), 66 out of 565 patients were identified who had additional maxillofacial radiographic examinations after the initial sialography. Additional radiographs up to October 2007 were included; these were orthopantomographic radiographs in all cases. In 28 patients (42%) signs of lipiodol retention were observed (mean radiographic follow-up: 15 ± 13 months). Retention was characterized by small radiopaque spots in the periphery of the gland. Lipiodol retention was predominantly associated with a fausse route (n = 8) or the presence of salivary gland disease (sialectasia; n = 17). In 9 patients with signs of lipiodol retention, a series of radiographs was available. Lipiodol radiodensities decreased in size during 28 months, and could disappear gradually (follow-up 14–57 months). Despite the high frequency of retention of small depots of lipiodol for years after sialography in patients subjected to additional radiographic examinations, no clinically adverse effects were observed.