Time-resolved three-dimensional technique for dynamic magnetic resonance dacryocystography

Comparing the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in NLDO-related acquired epiphora

PROPOSE

This study aimed to compare the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in the diagnosis of acquired epiphora related to NLDO. A total of 15 patients with acquired epiphora and suspected NLDO were included in this study.

METHODS

All patients underwent MRD and DSG examinations. MRD was performed using a 3-Tesla magnetic resonance imaging (MRI) scanner, while DSG involved injection of a radiotracer into the lacrimal drainage system followed by DSG. The results of both imaging methods were compared with the reference standard that was a combination of clinical examination findings and surgical exploration.

RESULTS

The results of this study showed that no abnormal findings were observed in MR-DCG in patients before the Valsalva maneuver. However, after the Valsalva maneuver, stenosis/obstruction at the canal surface was observed in all 15 patients diagnosed by DSG, giving a sensitivity of 100% for canal stenosis. Moreover, the results revealed that among these 15 patients, 9 showed stenosis or simultaneous obstruction at the level of the canal and lacrimal sac, but MR-DCG showed these lesions in only 9 patients, giving a sensitivity of 60%. The specificity of MRD and DSG were 85% and 76.7%, respectively. There was a statistically significant difference in the sensitivity of MRD and DSG (p < 0.05).

CONCLUSION

This study demonstrated that MRD has a higher diagnostic accuracy in the diagnosis of acquired epiphora associated with NLDO compared to DSG. MRD showed significantly higher sensitivity and specificity than DSG. Therefore, MRD can be considered as the preferred imaging modality in the diagnosis of acquired epiphora due to NLDO. By accurately identifying the underlying cause of NLDO, MRD can help determine the most appropriate treatment approach for patients and lead to better outcomes.

A Pilot Study of Dynamic Magnetic Resonance Dacryocystography Imaging to Assess Functional Epiphora

OBJECTIVE

To evaluate dynamic magnetic resonance dacryocystography (MRDCG) in eyes with functional epiphora.

METHODS

We included prospective eyes with epiphora if no alternative cause was found on clinical examination, were patent on syringing, had no obstruction or stenosis on DCG, and had an abnormal DSG. MRDCG was performed to qualitatively assess for block or patency and quantitatively measure tear transit time. We compared measurements to asymptomatic fellow eyes and to historical reference values from asymptomatic eyes.

RESULTS

We included 26 symptomatic eyes of 19 patients (median age 63 years). There was a block on MRDCG in 18 (69%) eyes and patency in 8 (31%) eyes. The block occurred at the sac-nasolacrimal duct (NLD) junction in 9 (50%), proximal NLD in 5 (28%), mid-NLD in 1 (5.6%), and distal NLD in 1 (5.6%) eye(s). No contrast was observed in the lacrimal system in two eyes. For eyes patent on MRDCG, median times to the sac, NLD, inferior meatus, first 25%, and first 50% of the fundus-to-nose distance (FND) were 22, 54, 118, 34, and 84 s, respectively. Times to the sac, NLD, and to fill the first 25% and 50% of the FND were significantly longer than historical values from asymptomatic lacrimal systems (p = 0.017, 0.050, 0.035, 0.017, respectively).

CONCLUSION

MRDCG shows a high rate of block in functional epiphora. However, DSG and MRDCG results may not always correlate. The improved temporal resolution of this emerging modality may be advantageous in the critical first 2 min of tear transit.

Non-contrast MR dacryocystography for the evaluation of epiphora and recurrent dacryocystitis: A preliminary study

INTRODUCTION

Obstruction of the lacrimal drainage represents a common ophthalmologic issue. The blockage may interest any level of the lacrimal drainage pathway, and it is important to find the site of obstruction to plan the most appropriate treatment. In this study, findings from magnetic resonance (MR) dacryocystography were compared with findings from endoscopic and surgical procedures to evaluate the accuracy of MR dacryocystography in localizing the site of nasolacrimal duct obstruction.

METHODS

We enrolled twenty-one patients with clinical suspicion of nasolacrimal duct obstruction who underwent dacryoendoscopy and surgery. MR dacryocystography was performed with a heavily T2-weighted fast spin echo sequence in the coronal planes. Before the MRI was performed, a sterile 0.9% NaCl solution was administered into both conjunctival sacs. For each examination, two independent readers (with 8 and 10 years of experience in head and neck imaging) evaluated both heavily 3D space T2-weighted and STIR sequences.

RESULTS

Stenosis/obstruction of nasolacrimal duct or lacrimal sac was diagnosed in all 21 patients who underwent MRI dacryocystography. In particular, the site of the obstruction was classified as lacrimal sac in 12 (57%) patients, nasolacrimal duct in 6 (29%) patients, and canaliculi in 3 (14%) patients by both readers. By comparison with the evidence resulting from the endoscopy, there were differences between MRI dacryocystography and dacryoendoscopy in the evaluation of the obstruction's site in three patients, with an overall accuracy of 85.7%.

CONCLUSION

MR dacryocystography allows a non-invasive evaluation of the lacrimal drainage pathway, valid for the planning of the most appropriate treatment.

DCR for nasolacrimal duct stenosis may be less effective than for complete obstruction

OBJECTIVES

To ascertain the success of endo-DCR in nasolacrimal duct stenosis (NLDS) versus nasolacrimal duct obstruction (NLDO).

METHODS

Consecutive adult patients with epiphora attending a tertiary lacrimal clinic from February 2012 to February 2021 were reviewed. NLDS was diagnosed by patent lacrimal syringing and combined dacryocystography (NLD stenosis) and dacryoscintigraphy (post-sac delay) findings in all eyes. Cases with evidence of canalicular stenosis or other identifiable causes of epiphora were excluded. The epiphora resolution and improvement rates following endo-DCR were compared between NLDS and complete NLDO cases.

RESULTS

DCRs in 24 NLDS (23 patients, 69.6% females, mean age 61.0 ± 17.07) and 58 NLDO (56 patients, 69.6% females, mean age 61.9 ± 17.4) were included. Resolution of epiphora was achieved in 10 (41.7% [95% CI 0.24-0.61]) of the NLDS cases compared to 40 (69.0% [95% CI 0.56-0.79]) in NLDO (p = 0.021). Improvement of epiphora (i.e., either improvement or resolution) was noted in 17 (70.8% [95% CI 0.51-0.85]) of NLDS and 53 (91.4% [95% CI 0.81-0.96]) of NLDO cases (p = 0.034). Three patients (12.5%) with NLDS had subsequent lacrimal procedures (one DCR revision, two Jones tube) at a median of 14 (range 11-21) months. 71.4% of the NLDS patients responded to a phone questionnaire at a median of 93 months postoperatively. Of these, 46.7% reported resolution or significant improvement, and 33.3% reported slight improvement. 64.3% said they would recommend DCR to others suffering from epiphora.

CONCLUSION

Endo-DCR may benefit approximately 70% of patients with NLDS. The success of endo-DCR in complete NLDO may be higher.

Differential subsampling with cartesian ordering: A high spatial-temporal resolution dixon imaging sequence for assessment of dural arteriovenous fistula

Objective

To evaluate the accuracy of differential subsampling with cartesian ordering (DISCO) in comparison to time of flight (TOF) in detecting dural arteriovenous fistulas (DAVF), cerebral venous thrombosis (CVT) and hemodynamics.

Methods

Sixty-two cases (24 female; aged 14–75; mean age, 51.3 years) were included in our study, with 42 positive and 20 negative cases via Digital Subtraction Angiography (DSA). Two neuroradiologists independently evaluated the DISCO and TOF. The sensitivity, specificity, and accuracy of the DISCO and TOF-MRA were individually calculated using DSA as the gold standard. Inter-observer reliability was assessed by using a weighted Cohen's kappa (κ) test; P < 0.05 was set as the threshold for statistical significance.

Results

Diagnostic sensitivities of DISCO and TOF for DAVF were 92.86 and 64.29%; specificities were 95.0% and 95.0%; while accuracies were 93.55 and 74.19% respectively. For detected CVT, sensitivities of DISCO and TOF were 100 and 92.31%; specificities were 96.55 and 93.10%; with accuracies 97.62 and 92.86% respectively. In hemodynamic analysis, sensitivity of DISCO for reflux was 95.45%; with a specificity of 95.0%; and accuracy 95.24%. The inter-observer kappa values were 0.857 for DISCO (P < 0.001).

Conclusion

DISCO showed a high degree of sensitivity and specificity, suggesting its effectiveness in detecting DAVF with or without CVT. Intracranial hemodynamics can be identified using DISCO in DAVF patients, providing accurate evaluation of cerebral blood flow dynamics during the pre-treatment phase.

High nasolacrimal sac-duct junction anatomical variation - retrospective review of dacryocystography images

PURPOSE

In assessing epiphora, dacryocystography (DCG) is often performed to determine the presence of any structural anomaly of the nasolacrimal drainage apparatus. We describe an anatomical variation of the nasolacrimal duct, termed high sac-duct junction (HSDJ) morphology, that is seen on DCG, which could lead to more difficult, and possibly unsuccessful, intubation of the nasolacrimal duct (NLD).

METHODS

This was a multi-center, retrospective, observational case series. Seven hundred and thirty-four DCGs were included in this study, of which 45 were pediatric images. DCG images underwent a blinded review by an oculoplastic surgeon for the presence of HSDJ morphology. The direct extension of the NLD from the inferior border of the lacrimal sac is commonly regarded as a normal morphology. HSDJ was defined as NLD originating from the inferior aspect of the medial wall of the lacrimal sac.

RESULTS

HSDJ was seen in 28/689 (4.1%) adult scans and 7/45 (15.6%) pediatric scans. In total, there were 35/734 (4.8%) DCGs demonstrating lacrimal sacs with HSDJ.

CONCLUSIONS

We report the prevalence of an anatomical variant of the lacrimal sac and NLD, observed on DCG, in a population of patients with epiphora, where the NLD originates from the inferior aspect of the medial wall of the lacrimal sac. Knowledge of this anatomic variant may have management implications for patients with epiphora as it may make nasolacrimal intubation more technically difficult. Further studies are needed to correlate this anatomic variation with symptoms and management outcomes.