Evaluation of epiphora by topical contrast-enhanced CT and MR dacryocystography: which one to choose?

Abstract

Our study aims to compare non-invasive imaging such as topical computed tomography dacryocystography (CTD) and topical magnetic resonance dacryocystography (MRD) in patients with epiphora. To evaluate the practicability of topical contrast media during helical CTD and topical saline during MRD to reveal obstruction in the nasolacrimal drainage system (NLDS). Twenty participants with nasolacrimal duct obstruction were observed for two years. Ten participants underwent CTD and the other 10 participants underwent MRD. Images were analyzed by two radiologists. Participants were also asked about the level of discomfort of the contrast material versus the saline solution. The NLDS was seen on both CTD and MRD. Very good agreement between the two observers (κ value > 0.81) was seen according to the κ statistics. CTD multiplanar and 3D images allowed for precise diagnosis of the point of obstruction whereas, the MRD did not require any contrast material and showed the point of obstruction. Saline was more comfortable for the patients than topical contrast (P < 0.05). Topical CTD and MRD are non-invasive techniques that can visualize the degree and level of obstruction in the NLDS than conventional invasive cannulation dacryocystography. CTD is useful in visualizing the point of obstruction and smaller drainage structures. However, it is a source of ionizing radiation to the lens. The benefit of MRD is that it requires no contrast or radiation; however, it is poor in depicting the bone anatomy and smaller drainage structures. Finally, saline was better tolerated by patients than topical contrast.