Dynamic MR dacryocystography in patients with epiphora.

OBJECTIVE

The purpose of this study was to investigate the diagnostic value of dynamic MRI dacryocystography (dMR-DCG) for the assessment of nasolacrimal drainage system (NLDS).

METHODS

The study population consisted of 35 patients with a history of epiphora. Each patient underwent bilateral dMR-DCG and conventional dacryocystography (DCG) to assess the NLDS. Two radiologists, who were unaware of the clinical data, evaluated the images separately for the level of obstruction at the nasolacrimal passage and the presence or absence of lacrimal sac dilatation. The findings from the dMRI-DCG and DCG images were compared. DCG was considered to be the gold standard imaging technique.

RESULTS

dMRI-DCG had a sensitivity of 90.5% and a specificity of 89.3% to detect nasolacrimal passage. In 24 out of 70 NLDS that were assessed, there was 100% agreement between the dMRI-DCG and DCG images in the detection of the obstructed level in the nasolacrimal pathway. The lacrimal sac dilatation finding detected by DCG was not observed by dMRI-DCG in only two patients, in whom there was a prior history of dacryocystorhinostomy (DCR) operation. These findings suggest that dMRI-DCG has 94.3% sensitivity and 100% specificity for the diagnosis of lacrimal sac dilatation.

CONCLUSION

dMRI-DCG is an easily performed, minimally invasive imaging technique to identify the presence or absence of obstruction and its level, and lacrimal sac dilatation in the evaluation of NLDS. dMRI-DCG does not require the use of contrast material and ionizing radiation and provides functional information by depicting dynamic behaviour. Thus, dMRI-DCG could be useful as a reliable diagnostic imaging technique in many patients prior to surgery.