3 DFT Magnetic Resonance Dacryocystography in the Evaluation of Epiphora

ABSTRACT

PURPOSE: To evaluate the feasibility of 3-dimensional Fourier transformation magnetic resonancedacryocystography (3DFT MR DCG MR DCG) and its diagnostic efficacy in patients with epiphora. MATERIALS AND METHODS: Three normal volunteers and ten patients complaining of epiphora were studied by MR DCG using 3DFT CISSand 3DFT FLASH techniques. In normal volunteers, MR DCG was obtained by instillation of diluted Gd-DTPA solutionsof different concentrations (Gd-DTPA saline=1100, 150, 125) using various instillation methods. In patientswith epiphora, MR DCG was compared with conventional D C G . RESULTS: In normal volunteers, the best image wasobtained with the continuous instillation method during MR scanning. In all normal volunteers, MR DCG demonstratedthe entire course of the nasolacrimal duct (NLD). In patients with epiphora, however, there were five cases inwhich MR DCG failed to visualize the NLD, as well as five cases of occlusion and two of stenosis at the level ofthe proximal NLD. These findings corresponded with conventional DCG findings as four cases of occlusion at thelevel of the common canaliculi, one case of lacrimal sac, five cases of occlusion and two cases of stenosis at thelevel of the proximal NLD. There was no significant difference between MR DCG findings using 3DFT CISS and 3DFTFLASH MR techniques. CONCLUSION: MR DCG can detect the correct level of obstruction and differentiate betweenocclusion and stenosis of the NLD in patients with obstruction of the lacrimal drainage system. It may be a usefuldiagnostic method for investigating complicated cases in which conventional DCG is not possible due topost-surgical or traumatic obstruction.