Computed tomographic‐dacryocystography (CT‐DCG) of the normal canine nasolacrimal drainage system with three‐dimensional reconstruction

Abstract

The aims of the study were (1) to quantify the influence of selected imaging parameters on the image quality (slice thickness, mAs, and beam orientation) defining optimal conditions for scan protocols and (2) to evaluate the benefits of the 3D reconstruction techniques for visualization of NDS structures in dogs. CT-DCG was performed bilaterally in 32 heads of dogs. CT transverse images were obtained using a combination of two slice thickness values (0.8 mm and 2 mm) and two mAs values (50 mAs and 300 mAs). Two beam projection orientations were also tested: transverse plane (perpendicular to the hard palate) and oblique to the hard palate. Three-dimensional images were obtained using Volume Rendering (VR). Transverse beam projection proved to be superior for the assessment of the inferior and superior lacrimal canaliculi and lacrimal sac. In this study, there was no statistical difference regarding mAs values (50 mAs and 300 mAs) and slice thickness values (0.8 mm and 2 mm). Three-dimensional images were helpful for the assessment of topographic relationship between nasolacrimal structures and cranial landmarks.

The nasolacrimal duct of the mule: Anatomy and clinical considerations

“…Computed tomography is superior to radiography when evaluating the skull and CT-DCG has proven superior to radiographic dacryocystorhinography in the evaluation of the nasolacrimal apparatus for the presence of disease (Nykamp et al 2004;Cleary et al 2011;Rached et al 2011). In this study, the morphology of the ducts was similar in all mules and appeared to be normal.…”

“…; Rached et al . ). In this study, the morphology of the ducts was similar in all mules and appeared to be normal.…”

Avaliação da epífora de cães usando dacriocistografia e tomografia computadorizada

“…Esta avaliação é realizada pela dacriocistografia (DCG) contrastada, tomografia computadorizada ou ressonância magnéti-ca. Os resultados do presente trabalho também corroboram com os autores Rached et al (2011), que concluíram que a DCG-TC é uma ferramenta de diagnóstico útil para a avaliação do sistema nasolacrimal. Nykamp et al (2004) também defenderam que a TC é usada em epífora crônica e permite informações pertinentes que auxiliam no diagnóstico e/ou permitindo melhor apuramento no prognóstico.…”

“…A dacriocistografia por tomografia computadorizada tem mostrado ser a técnica mais confiável para descrever a anatomia do ducto lacrimonasal com alta resolução espacial (Rached et al 2007).…”

Dacryocystography in a cat with orbital pneumatosis

“…In cats, DCG was employed to assess the anatomic course of the nasolacrimal duct in brachycephalic breeds . Computed tomography dacryocystography (CT‐DCG) has recently been reported in dogs and cats . Compared with conventional dacryocystography, CT‐DCG provides superior assessment of the nasolacrimal anatomy and the relationship between the nasolacrimal duct and the surrounding structures of the skull, particularly if the exam is performed using a helical multislice CT scanner .…”