Non-contrast MR dacryocystography for the evaluation of epiphora and recurrent dacryocystitis: A preliminary study

Abstract

Introduction: Obstruction of the lacrimal drainage represents a common ophthalmologic issue. The blockage may interest any level of the lacrimal drainage pathway, and it is important to find the site of obstruction to plan the most appropriate treatment. In this study, findings from magnetic resonance (MR) dacryocystography were compared with findings from endoscopic and surgical procedures to evaluate the accuracy of MR dacryocystography in localizing the site of nasolacrimal duct obstruction.

Methods: We enrolled twenty-one patients with clinical suspicion of nasolacrimal duct obstruction who underwent dacryoendoscopy and surgery. MR dacryocystography was performed with a heavily T2-weighted fast spin echo sequence in the coronal planes. Before the MRI was performed, a sterile 0.9% NaCl solution was administered into both conjunctival sacs. For each examination, two independent readers (with 8 and 10 years of experience in head and neck imaging) evaluated both heavily 3D space T2-weighted and STIR sequences.

Results: Stenosis/obstruction of nasolacrimal duct or lacrimal sac was diagnosed in all 21 patients who underwent MRI dacryocystography. In particular, the site of the obstruction was classified as lacrimal sac in 12 (57%) patients, nasolacrimal duct in 6 (29%) patients, and canaliculi in 3 (14%) patients by both readers. By comparison with the evidence resulting from the endoscopy, there were differences between MRI dacryocystography and dacryoendoscopy in the evaluation of the obstruction's site in three patients, with an overall accuracy of 85.7%.

Conclusion: MR dacryocystography allows a non-invasive evaluation of the lacrimal drainage pathway, valid for the planning of the most appropriate treatment.

Keywords: MR dacryocystography; dacryocystitis; lacrimal drainage pathway; lacrimal sac; magnetic resonance imaging.

Figure 1.

Images obtained in a healthy volunteer: heavily T2-weighted 3D coronal sequence (a) and 3D coronal STIR (b) showing fluid-filled nasolacrimal ducts with normal caliber (yellow arrows). No signs of dilated lacrimal sacs.

Figure 2.

65-year-old female patient affected by right recurrent dacryocystitis. The T2-weighted image (a) showed a dilated lacrimal sac (arrowhead), with mild dilation of the inferior and superior canaliculi (white arrows). Axial (b, d) and coronal (c) reconstructions of the STIR images. In (b) the dilatation of the lacrimal sac is detectable (arrowhead). The left nasolacrimal duct is regularly filled with fluid (c, orange arrow), whereas the right nasolacrimal duct is empty (blue arrow): this finding is also visible in (d), where the axial image shows the fluid content of the left nasolacrimal duct (orange circle), whereas the left one is empty (blue circle). The obstruction was diagnosed in the nasolacrimal duct and confirmed by the endoscopy.

Figure 3.

73-year-old female patient affected by bilateral recurrent dacryocystitis. Axial (a, b, c) and coronal (d) reconstructions of the STIR images. Bilateral dilatation of the lacrimal sacs (a, b) (yellow arrowheads). The right lacrimal ducts present a fistulization (light blue arrowhead) with subcutaneous fluid collection (green arrowhead) (a). Both nasolacrimal ducts are filled with fluid (c, d, yellow arrows). The stenosis was diagnosed as located in the lacrimal sac and confirmed by endoscopy.

Figure 4.

Coronal MIP reconstruction of the heavily T2-weighted 3D coronal sequence (a) and axial MIP reconstruction of the heavily T2-weighted 3D coronal sequence (b) show stenosis of the common right canaliculus, with retro dilation of the common and inferior canaliculi (yellow arrows). Contralateral dilatation of the lacrimal sac (yellow arrowhead). Axial reconstructions of the 3D STIR sequence (c, d) show bilateral empty lacrimal ducts (blue circles). The patient was diagnosed as having stenosis located at the right common canaliculus and stenosis located at the left lacrimal sac.

Figure 5.

A 42-year-old patient with recurrent episodes of right dacryocystitis. (a) Huge distension of the right lacrimal sac (yellow arrow), with evidence of stenosis (yellow arrowhead) at the level with the conjunction to the nasolacrimal duct. (b) Shows that the right duct is empty (blue arrow), whereas the left one is filled with fluid (orange arrow). In Supplementary Materials, we uploaded the video of the surgical procedure.