Technical note: computed tomographic dacryocystography.

The technique of computed tomographic dacryocystography is described. It was developed in response to the pre-operative imaging requirements for transnasal endoscopic dacryocystorhinostomy, a new minimally invasive operation performed as a primary procedure to relieve epiphora. However, it is also helpful in the assessment of patients after failed conventional external dacryocystorhinostomy when the information provided will help to determine the subsequent surgical approach. In addition the technique will assist surgical planning in cases of epiphora associated with sinus surgery, facial trauma and maxillofacial tumours by determining the site and extent of pathology.