# The novel diagnostic value and characteristic imaging features of CT dacryocystography in primary lacrimal canaliculitis

## TL;DR

CT dacryocystography shows unique imaging features and high accuracy in diagnosing primary lacrimal canaliculitis, outperforming traditional methods.

## Contribution

CT-DCG is shown to have high sensitivity and specificity for diagnosing primary canaliculitis with distinct imaging features.

## Key findings

- CT-DCG showed 94.4% sensitivity and 98.5% specificity for diagnosing canaliculitis.
- Filling defects were identified as a key diagnostic feature in CT-DCG imaging.
- High inter-observer agreement (Cohen’s kappa = 0.85) was observed in CT-DCG assessments.

## Abstract

To analyze the imaging characteristics and evaluate the diagnostic value of computed tomographic dacryocystography (CT-DCG) in primary canaliculitis. This is a retrospective study from three medical centers. We enrolled 126 primary canaliculitis patients (126 eyes) and 108 non-canaliculitis subjects (134 eyes). All patients with canaliculitis underwent CT-DCG, dacryoendoscopy examination, microbiologic culture, histopathologic staining and canaliculotomy to confirm the definitive diagnosis. Non-canaliculitis cases were diagnosed via dacryoendoscopy and CT-DCG. Demographics, clinical features, and CT-DCG imaging features of primary canaliculitis were evaluated. The diagnostic performance, including sensitivity, specificity, and inter-observer agreement, was also assessed. In the canaliculitis group, the main imaging characteristics of CT-DCG included filling defects, dilation, raggedness, beading, and diverticula formation. Filling defects can serve as a distinctive diagnostic feature of canaliculitis. In our series, CT-DCG showed excellent diagnostic performance with a sensitivity of 94.4%, specificity of 98.5%, and high inter-observer agreement (Cohen’s kappa = 0.85). CT-DCG demonstrates distinct imaging features that enable accurate diagnosis of primary lacrimal canaliculitis. It overcomes limitations of traditional methods, provides comprehensive LDS visualization, and offers valuable preoperative information, establishing it as a superior diagnostic tool.