Sialolithiasis and salivary ductal stenosis: Diagnostic accuracy of MR sialography with a three-dimensional extended-phase conjugate-symmetry rapid spin-echo sequence

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) sialography in detecting salivary glandular calculi and ductal stenoses. MATERIALS AND METHODS: In a prospective study, 64 salivary glands in 61 con secutive patients with acute or recurrent parotid or submandibular glandula r swelling were examined by using three-dimensional 3D) extended-phase-conj ugate-symmetry rapid spin-echo (EXPRESS) MR imaging. Transverse and sagitta [oblique source images and maximum intensity projection images were obtaine d. All MR images were analyzed independently by two radiologists, without k nowledge of the final diagnosis. The reference standard was conventional si alography, ultrasonography (US), and sialendoscopy with or without surgery in 31 glands and was conventional sialography and US in 33 glands. RESULTS: Final diagnoses included sialolithiasis (n = 23), sialolithiasis a nd stenosis (n = 9), stenosis without lithiasis (n = 11), early Sjogren syn drome without ductal stenosis (n = 2), ductal displacement (n = 3), and nor mal salivary glands (n = 16). The sensitivity, specificity, and positive an d negative predictive values of MR sialography to detect calculi were 91%, 94%-97%, 93%-97%, and 91%, respectively. False-negative readings occurred d ue to calculi with a diameter of 2-3 mm in nondilated salivary ducts. Ducta l stenosis was assessed, with a sensitivity of 100%, specificity of 93%-98% , positive predictive value of 87%-95%, and negative predictive value of 10 0%. Interobserver agreement was very good (kappa = 0.85-0.97). CONCLUSION: MR sialography with 3D EXPRESS imaging enables reliable predict ion of salivary gland calculi and stenoses.