Three-dimensional cone-beam computed tomographic sialography in the diagnosis and management of primary Sjögren syndrome: Report of 3 cases

A comparative study of three-dimensional cone-beam CT sialography and MR sialography for the detection of non-tumorous salivary pathologies

BACKGROUND

Imaging of the salivary ductal system is relevant prior to an endoscopic or a surgical procedure. Various imaging modalities can be used for this purpose. The aim of this study was to compare the diagnostic capability of three-dimensional (3D)-cone-beam computed tomography (CBCT) sialography versus magnetic resonance (MR) sialography in non-tumorous salivary pathologies.

METHODS

This prospective, monocenter, pilot study compared both imaging modalities in 46 patients (mean age 50.1 ± 14.9 years) referred for salivary symptoms. The analyses were performed by two independent radiologists and referred to identification of a salivary disease including sialolithiasis, stenosis, or dilatation (primary endpoint). The location and size of an abnormality, the last branch of division of the salivary duct that can be visualized, potential complications, and exposure parameters were also collected (secondary endpoints).

RESULTS

Salivary symptoms involved both the submandibular (60.9%) and parotid (39.1%) glands. Sialolithiasis, dilatations, and stenosis were observed in 24, 25, and 9 patients, respectively, with no statistical differences observed between the two imaging modalities in terms of lesion identification (p1 = 0.66, p2 = 0.63, and p3 = 0.24, respectively). The inter-observer agreement was perfect (> 0.90) for lesion identification. MR sialography outperformed 3D-CBCT sialography for visualization of salivary stones and dilatations, as evidenced by higher positive percent agreement (sensitivity) of 0.90 [95% CI 0.70-0.98] vs. 0.82 [95% CI 0.61-0.93], and 0.84 [95% CI 0.62-0.94] vs. 0.70 [95% CI 0.49-0.84], respectively. For the identification of stenosis, the same low positive percent agreement was obtained with both procedures (0.20 [95% CI 0.01-0.62]). There was a good concordance for the location of a stone (Kappa coefficient of 0.62). Catheterization failure was observed in two patients by 3D-CBCT sialography.

CONCLUSIONS

Both imaging procedures warrant being part of the diagnostic arsenal of non-tumorous salivary pathologies. However, MR sialography may be more effective than 3D-CBCT sialography for the identification of sialolithiasis and ductal dilatations.

TRIAL REGISTRATION

NCT02883140.

A comparative study of three-dimensional cone beam computed tomographic sialography and ultrasonography in the detection of non-tumoral salivary duct diseases

OBJECTIVES

To compare the overall diagnostic outcomes of 3D-CBCT sialography and ultrasonography (US) in the detection of sialolithiasis, ductal dilatation, and ductal stenosis.

METHODS

This retrospective monocentric study compared the two imaging modalities carried out in the same patients referred for salivary symptoms of the parotid and submandibular glands. The primary endpoint was the capacity of the imaging procedure to diagnose a lesion. The secondary objectives were the detection rates according to the type of lesion, analysis of the causes of failure, and the parameters of radiation exposure and safety (for 3D-CBCT sialography).

RESULTS

Of the 236 patients who received a 3D-CBCT sialography in our institution, 157 were ultimately included in the per-protocol analysis. 3D-CBCT sialography allowed detection of ductal lesions in 113 patients versus 86 with US. The two imaging modalities yielded congruent interpretations in 104 out of 157 subjects (66.2%). Higher sensitivity and negative predictive value were observed with 3D-CBCT sialography compared with US, irrespective of the lesions studied: 0.85 vs 0.65 and 0.70 vs 0.44, respectively. Regarding the sialolithiasis, both 3D-CBCT sialography and US allowed identification of lesions with high sensitivity and negative predictive value (0.80 vs 0.75 and 0.88 vs 0.78, respectively).

CONCLUSIONS

US remains the first-line examination for exploration of the salivary lesions. 3D-CBCT sialography is an alternative in case of inconclusive US, and prior to any endoscopic procedure.

Sialography: a pictorial review

Non-tumour inflammatory and obstructive salivary gland pathologies such as sialadenitis, sialolithiasis, sialadenosis, ductal strictures, etc. require precise radiological evaluation and mapping of salivary gland ductal system for better treatment outcome. Conventional sialography is considered as a useful and reliable technique in evaluation of salivary glands especially intrinsic and acquired abnormalities involving the ductal system and is useful for detection of non-radiopaque sialoliths which are invisible on routine plain radiographs. Primarily sialography is used as a diagnostic tool, additionally it plays an important therapeutic role as salivary gland lavage in cases of recurrent salivary gland infections and in obstructive salivary gland disorders by helping in clearance of mucous plugs or small sialoliths within the ducts. Recently, diagnostic performance of computed tomography (CT) sialography is being explored and has been reported to have high sensitivity in detection of small sialoliths and allows differentiation of sialoliths from other calcifications in glandular ductal system. Multiplanar three dimensional (3D) reconstructed CT images have been reported to play a key role in determination of anatomical location or extent of salivary gland disease without superimposition or distortion of structures. This review aims to discuss the disease specific applications of sialography and CT Sialography in particular for visualization of salivary gland disorders.

Anatomical Features of the Parotid Duct in Sialography as an Aid to Endoscopy—A Retrospective Study

Sialography is used for diagnosis of obstructive salivary gland diseases and prior to sialendoscopy. Three-dimensional cone beam computerized tomography (CBCT) sialography allows imaging and measurement of salivary duct structures. Salivary gland endoscopy has a long learning curve. The aim of this retrospective study is to create an anatomical quantitative guide of different distances and angles significant for endoscopy. Twenty-six CBCT sialographies of healthy parotid ducts were included. Outcome parameters included diameters, distances, angles and number of minor tributaries. Results show the average distance from the papilla to the curvature of the gland was 41.5 mm (Q1 36.97 mm–Q3 45.32 mm), with an angle of 126.9° (Q1 107.58°–Q3 135.6°) of the curvature and a distance of 35.25 mm (±7.81 mm) between the curvature and the hilus. The mean width of the duct was 0.8 mm (Q1 0.7 mm–Q3 1.15 mm) at its narrowest and 2 mm (Q1 1.4 mm–Q3 2.2 mm) at its widest. This is the first anatomical quantitative study of the parotid duct in relation to sialendoscopy.