What is Dacryocystography ?

• -term used to denote radiologic examination of nasolacrimal drainage system
• -done by filling the lumina of the canals with radiopaque medium
• -performed in the investigation of abnormalities of the passage as defective development, stenosis and chronic mucosal thickening

Examination Procedure

This preliminary radiograph are taken to evaluate the paranasal sinuses

1. Waters
2. Caldwell
3. Lateral

• to expedite filming after the introduction of contrast medium, injection is carried out with patient seated before a vertical grid device
• patient may however be placed in supine position for introduction of medium and prone position for filming
• after anesthetizing the conjunctiva and puncta, physician dilates the punctum of the canaliculus to be injected
• then inserts the round-tipped lacrimal needle into the canaliculus.
• patency of the canals is tested by irrigating them with normal saline solution and if fund patent, examination is terminated
• immediately following the introduction of the contrast agent and withdrawal of needle, radiographs are taken in rapid succession in Caldwell, waters and lateral position
• same images are repeated at specified intervals to follow the progress of the medium though the channels.
• 7-10 minutes of post injection interval are taken for follow-up radiograph and again 15-20 minutes interval at which the medium will passed through the patient ducts and seen on the floor of the nasal cavity and on pharyngeal mucosa
• collateral side may be injected after the initial filming of the 1st side and its necessary to rotate head slightly (10-15º) away from the film in order to separate the shadow of bilaterally opacified ducts in lateral projection
• exposure factors used for routine paranasal sinus studies are satisfactory for the contrast studies of nasolacrimal duct system