The MR Imaging Assessment of Submandibular Gland Sialoadenitis Secondary to Sialolithiasis: Correlation with CT and Histopathologic Findings

MR imaging has been proved to be effective in depicting wide variety of pathologic changes of the salivary gland. Therefore, we evaluated clinical usefulness of MR imaging for sialolithiasis. Sixteen patients with sialolithiasis of the submandibular gland underwent MR imaging. MR images of the glands were obtained with a conventional (T1-weighted), fast spin-echo (fat-suppressed T2-weighted) and short inversion time-inversion recovery sequences. Contrast enhancement was not used. MR imaging features then were compared with clinical symptoms, histopathologic features of excised glands, and CT imaging features. Submandibular glands with sialolithiasis could be classified into three types on the basis of clinical symptoms and MR imaging features of the glands. Type I glands were positive for clinical symptoms and MR imaging abnormalities, and were characterised histopathologically by active inflammation (9 [56%] of 16). Type II glands were negative for clinical symptoms and positive for MR imaging abnormalities (4 [25%] of 16), and the glands were replaced by fat. Type III glands were negative for clinical symptoms and MR imaging abnormalities (3 [19%] of 16). CT features of these glands correlated well with those of MR imaging. These results suggest that MR imaging features may reflect chronic and acute obstruction, and a combination of CT and MR imaging may complement each other in examining glands with sialolithiasis.