This study was conducted to assess the utility of dynamic MR dacryocystography in the evaluation of the behavior of the lacrimal gland duct after injection of Antirex (edrophonium chloride), and to estimate the lacrimal gland function in patients with Sjogren syndrome. Dynamic MR dacryocystography was obtained using a single-shot RARE sequence with a 4-cm-diameter surface coil. Imaging parameters were : echo spacing=11.5 msec, effective TE=1100 msec, ETL=240, slab thickness=30 mm, FOV=169X169 mm, image matrix=240X256, in-plane resolution=0.70X0.66 mm, NEX=1, acquisition time=7.1 sec. Immediately after intravenous injection of Antirex, sequential MR dacryocystograms were obtained. Eight control subjects and 48 patients suspected of having Sjogren syndrome with symptoms of dry eye were included in this study. Labial gland biopsy and Schirmer's test were performed in all patients. Morphologic and functional evaluation of dynamic MR dacryocystography was performed and comparative study with the results of labial gland biopsy and Schirmer's test was done. In control subjects, the lacrimal sac was seen soon after the injection of Antirex, thereafter the nasolacrimal duct was gradually demonstrated. In patients suspected of having Sjogren syndrome, delayed or lack visualization of lacrimal sac and nasolacrimal duct was seen on dynamic MR dacryocystography. Significant correlation was present between the results of dynamic MR dacryocystography and Schirmer's test (p<.001). Also there was correlation between the results of dynamic MR dacryocystography and labial gland biopsy (p<.01). We conclude that dynamic MR dacryocystography after injection of Antirex provides detailed, physiologic information about the conditions of lacrimal gland in patients with Sjogren syndrome.