A comparison of conventional and diffusion-weighted magnetic resonance imaging in the diagnosis of sialadenitis and pleomorphic adenoma.

OBJECTIVES: The aim of this study was to compare the efficacy of conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in correctly identifying the presence of disease in the major salivary glands and correctly distinguish sialadenitis from pleomorphic adenoma. STUDY DESIGN: Twenty-one patients diagnosed with unilateral sialadenitis or pleomorphic adenoma were selected. The nonaffected contralateral glands were also analyzed. T1- and T2-weighted MRI and DWI were obtained using spin-echo pulse sequences with a 1.5 Tesla MRI device. The diagnostic performance of 3 observers was evaluated for detection of salivary gland alterations and differentiation between sialadenitis and pleomorphic adenoma based on evaluation of MRI in comparison with DWI. RESULTS: Intra-and interobserver reliability ranged from 0.86 to 0.94. DWI demonstrated greater sensitivity and accuracy values compared with MRI for both detection of disease and differentiation of sialadenitis from pleomorphic adenoma, with specificity values that were greater than or equal to those of MRI. DWI yielded significantly higher diagnostic odds ratios compared with MRI for both identification of disease and differentiation between lesions. CONCLUSIONS: DWI demonstrated better diagnostic performance in the detection of alterations in the salivary glands and in differentiating between sialadenitis and pleomorphic adenoma compared with conventional T1 and T2-weighted MRI.