The role of MRI in facial swelling due to presumed salivary gland disease.

50 consecutive patients presenting with facial swelling thought clinically to be due to salivary gland disease underwent MRI. Examinations were interpreted by one radiologist without access to previous investigations. Records were reviewed to determine the reliability and role of MRI in patient management, and the contribution of other prior or subsequent investigations. MRI findings were verified against operative findings, percutaneous biopsy or clinical follow-up (periods ranging from 8-58 months). A mass was found in 27 patients; in 11 of these patients, disease was extrinsic to the salivary gland. MRI diagnosis of tumour was correct in all patients and MRI was a reliable investigation for planning surgical resection. No mass was found in 23 patients, 8 of whom had normal appearances. Evidence of salivary duct dilatation was seen in 12 patients and fatty infiltration was seen in 3. MRI findings appeared correct in all patients. Prior investigation was undertaken in 29 patients, including orthopantomography, ultrasound and sialography; none provided additional information. Sialography was carried out in three patients after MRI and concurred with MRI in all cases. MRI was an adequate basis for management in all patients and therefore appears to be an effective first line investigation of facial swelling. It is reasonable for patients to undergo preliminary investigation for dental sepsis, this being the most common cause of facial swelling. Further study is required to determine whether MRI can completely replace invasive sialography.