[A new possibility for imaging the lacrimal draining system. Three-dimensional rotation dacryocystography]

Abstract

Background: The aim was to investigate the applicability of a 3D rotation angiography system for imaging lesions of the lacrimal draining system.

Patients and methods: Five patients with stenosis of the lacrimal system were enrolled in this pilot project to undergo a distension dacryocystography as 3D rotation angiography. The 3D reconstructions are derived from 100 radiographic projection images, which are obtained during a 240 degrees rotation of an angiographic C-arm. Volume-rendering techniques show plastic representations of the contrast-enhanced ductal system with the possibility of additional virtual dacryoendoscopy. The adjacent bony structures and the nasal cavity can also be visualized by special window settings and cuts through the 3D data set. Exact calibration of the X-ray system allows for precise measurements of distances. A sufficient 3D representation needs permanent injection of contrast material for about 5.5 s. Outpatient examination under surface anesthesia is well tolerated.

Results: The high-resolution 3D reconstructions show detailed images of lesions of the endoluminal surface and give a plastic impression of the site of obstructions. In contrast to normal DSA dacryocystography, the contrast-enhanced ductal system, the adjacent bone, and even the soft tissues of the nasal cavity are demonstrated simultaneously. A disadvantage is an incomplete representation of the residual lumen of subtotal stenoses and the one and one-half times higher radiation dose compared to normal dacryocystography.

Conclusion: Dacryocystography with 3D rotation angiography opens a new dimension of minimally invasive imaging of the lacrimal drainage system, which may be helpful for exact planning of dacryocystorhinostomy procedures.