Dacryocystoscintigraphy: Diagnosis of Lacrimal Duct Obstruction Using Pinhole Collimator

Radiologic studies of the nasolacrimal system following instillation of various opaque media have been found to be of value in patients with epiphora. However, there are certain disadvantages with these methods. Extravasation of the oily opaque media into the surrounding tissues may subsequently result in the development of pseudopolycystic sacs. The use of too highly concentrated solutions of aqueous contrast substances occasionally results in local irritation. Although improved contrast preparations are now available for studies of the nasolacrimal system, injection directly into the duct is necessary. A local anesthetic is required before the introduction of the contrast material through a dilator or cannula. Recently, scintigraphic study of the nasolacrimal system has been described using a micro pinhole collimator (0.04-in. or 1-mm diameter) ( 1 ). This method was found to be convenient and valuable to evaluate the patency of the nasolacrimal duct. Since the micro pinhole collimator is not readily available, we have used a standard pinhole collimator (5 mm). In this report we describe our technique of performing a dacryocystoscintigram with the standard pinhole collimator in 16 patients referred to our department with complaints of epiphora. The results are discussed briefly, for the clinical and scintigraphic details are to be published elsewhere.