Advances in imaging of obstructed salivary glands can improve diagnostic outcomes

Sialendoscopy Findings Associated with Positive Minor Salivary Gland Biopsy

OBJECTIVES

To determine the sialendoscopy findings associated with positive findings on minor salivary gland biopsy.

STUDY DESIGN

Single-center retrospective study.

METHODS

Patients ≥18 years old who underwent sialendoscopy from 2016 to 2022 and were evaluated for SS via labial minor salivary gland biopsy. Biopsy positive and negative patients were compared on the primary outcome measure of sialendoscopy findings. Data were abstracted from the sialendoscopy operative notes and included involved gland, location of ductal pathology, and the presence of scarring, stenosis, mucus plugs, webs, and dilations. Additional characteristics included demographics, presenting symptoms, caffeine or tobacco, use of drying medications, and need for additional treatments.

RESULTS

The final cohorts included 22 biopsy positive and 21 biopsy negative patients with a total of 42 glands in the biopsy positive and 37 glands in the biopsy negative groups. Biopsy positive patients were found to require dilation at the hilum and distal duct at significantly higher rates than biopsy negative patients (p < 0.0001). However, there was no statistical difference in scarring, stenosis severity, mucus, webs, or dilations between each group.

CONCLUSION

The outcomes of this study suggest that there are no distinct sialendoscopy findings associated with biopsy positive patients. The presence of significant distal stenosis on sialendoscopy may be associated with positive minor salivary biopsy. Other endoscopic parameters are likely more consistent with non-specific chronic sialadenitis.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1183-1189, 2024.

Gadolinium as a contrast agent for infusion sialograms in patients with iodine allergy

Objectives

To assess the adequacy of gadolinium in sialography as an alternative contrast agent for patients with iodine allergies. To directly compare images taken with gadolinium versus iodine-based contrast agents using the Iowa Sialography Classification System.

Methods

Retrospective chart review was performed on patients undergoing sialography between February 2008 and July 2022. Patients with sialograms obtained with gadolinium were identified and matched to similar sialograms obtained with iodine-based contrast agent. Patients were matched based on duct location, duct side, and initial radiology findings. Blinded reevaluation of sialograms was performed first independently and then by consensus by two head and neck radiologists to evaluate overall image adequacy and grade using the Iowa Sialography Classification System.

Results

Four patients with six sialograms (one bilateral parotid and one parotid + submandibular) obtained with gadolinium were identified and reevaluated. Five patients with six sialograms (one bilateral parotid) obtained with iodine-based were matched to the gadolinium sialograms. The overall adequacy of images for gadolinium sialograms was graded at an average of 4.25 (4 = good and 5 = excellent); whereas, the overall adequacy of iodine-based sialograms was graded at an average of 5. Inter-observer variability was observed in three sialograms obtained with gadolinium (50%), while no interobserver variability was observed in sialograms obtained with iodine-based contrast agent.

Conclusion

Gadolinium is an adequate alternative to use in sialography for patients with iodine allergies undergoing contemporary digital infusion sialography. Adverse reactions to iodine contrast agents are rare in sialography; however, the precautionary use of gadolinium is acceptable for the diagnostic and therapeutic benefits in sialography.Level of Evidence: IV.

The clinical anatomy of the accessory submandibular gland: a comprehensive review

An accessory submandibular gland is a rare variation. As such, there is limited literature regarding the embryology, anatomy, variations, clinical imaging, and pathology of the accessory submandibular gland. In this article, we review the existing literature on the accessory submandibular gland from clinical and anatomical perspectives. The goal of this review is to provide comprehensive knowledge of this variation which can be useful for oral and maxillofacial/head and neck surgeons, radiologists, and anatomists. Within this review, the embryologic origin as well as the anatomy of the accessory submandibular gland is detailed. Several imaging modalities which can be used to visualize the accessory submandibular gland are outlined as well as its variations. Lastly, this review investigates several reported clinical considerations regarding the accessory submandibular gland including sialoliths, Wharton's duct obstruction, and pleomorphic adenoma.

Epidemiologic, radiologic, and sialendoscopic aspects in chronic obstructive sialadenitis

PURPOSE

Chronic obstructive sialadenitis (COS) is a recurring inflammation of the salivary gland. To date, there are no known predisposing factors for COS. Given the advances seen in radiology and sialendoscopy, we must update our knowledge of COS, analyzing factors that can favor its development.

METHODS

We prospectively analyzed 333 patients who underwent sialendoscopy between 2012 and 2021. Epidemiologic, radiologic, and sialendoscopy-related factors were correlated. Suspected diagnosis was established based on the clinical and radiologic data. The final diagnosis was determined on the basis of sialendoscopic findings.

RESULTS

The most common etiology of COS was stricture (40.8%). Lack of papilla distensibility (LPD) was also described as an etiology. COS was related to patient gender and age. Submandibular gland involvement was significantly more associated with lithiasis and LPD, while COS of the parotid gland was most frequently caused by stricture. Radioiodine sialadenitis and Sjögren's syndrome were significantly associated with stricture. MR sialography (MR-Si) showed the best overall sensitivity and specificity.

CONCLUSION

In our series, stricture was the most common cause of COS. We describe LPD as a frequent cause of COS in this series; ours is the first study to report this finding. There was a significant association between the salivary gland involved, patient sex and age, and the cause of COS. MR-Si showed the greatest diagnostic yield.

Comparison of detection performance of soft tissue calcifications using artificial intelligence in panoramic radiography

Artificial intelligence (AI) is limited to teeth and periodontal disease in the dental field, and is used for diagnosis assistance or data analysis, and there has been no research conducted in actual clinical situations. So, we created an environment similar to actual clinical practice and conducted research by selecting three of the soft tissue diseases (carotid artery calcification, lymph node calcification, and sialolith) that are difficult for general dentists to see. Therefore, in this study, the accuracy and reading time are evaluated using panoramic images and AI. A total of 20,000 panoramic images including three diseases were used to develop and train a fast R-CNN model. To compare the performance of the developed model, two oral and maxillofacial radiologists (OMRs) and two general dentists (GDs) read 352 images, excluding the panoramic images used in development for soft tissue calcification diagnosis. On the first visit, the observers read images without AI; on the second visit, the same observers used AI to read the same image. The diagnostic accuracy and specificity for soft tissue calcification of AI were high from 0.727 to 0.926 and from 0.171 to 1.000, whereas the sensitivity for lymph node calcification and sialolith were low at 0.250 and 0.188, respectively. The reading time of AI increased in the GD group (619 to 1049) and decreased in the OMR group (1347 to 1372). In addition, reading scores increased in both groups (GD from 11.4 to 39.8 and OMR from 3.4 to 10.8). Using AI, although the detection sensitivity of sialolith and lymph node calcification was lower than that of carotid artery calcification, the total reading time of the OMR specialists was reduced and the GDs reading accuracy was improved. The AI used in this study helped to improve the diagnostic accuracy of the GD group, who were not familiar with the soft tissue calcification diagnosis, but more data sets are needed to improve the detection performance of the two diseases with low sensitivity of AI.

Salivary and lacrimal dysfunction after radioactive iodine for differentiated thyroid cancer: American Head and Neck Society Endocrine Surgery Section and Salivary Gland Section joint multidisciplinary clinical consensus statement of otolaryngology, ophthalmology, nuclear medicine and endocrinology

BACKGROUND

Postoperative radioactive iodine (RAI) administration is widely utilized in patients with differentiated thyroid cancer. While beneficial in select patients, it is critical to recognize the potential negative sequelae of this treatment. The prevention, diagnosis, and management of the salivary and lacrimal complications of RAI exposure are addressed in this consensus statement.

METHODS

A multidisciplinary panel of experts was convened under the auspices of the American Head and Neck Society Endocrine Surgery and Salivary Gland Sections. Following a comprehensive literature review to assess the current best evidence, this group developed six relevant consensus recommendations.

RESULTS

Consensus recommendations on RAI were made in the areas of patient assessment, optimal utilization, complication prevention, and complication management.

CONCLUSION

Salivary and lacrimal complications secondary to RAI exposure are common and need to be weighed when considering its use. The recommendations included in this statement provide direction for approaches to minimize and manage these complications.

Sialographic analysis of parotid ductal abnormalities associated with Sjogren's syndrome

OBJECTIVES

To analyze the location and degree of parotid ductal abnormalities associated with Sjogren's syndrome (SS) and to correlate findings with the duration of the disease. To develop a classification system based on contemporary sialography techniques and employ the system to grade findings on sialograms. To assess the role for therapeutic intervention in patients with SS.

METHODS

Retrospective chart review of a consecutive series of 337 sialograms done by the senior investigator over a 10-year period identified 26 sialograms in patients who met the criteria for SS as defined by the American-European Consensus Group (2002). A classification system was developed to grade the degree of ductal abnormalities identified on the sialograms. Individual, initial blinded review of these sialograms was performed by two head and neck radiologists to identify and grade abnormalities. Radiographic findings were correlated with patient history including symptom duration.

RESULTS

All patients with SS had stenoses within the ductal system. About 73.1% of patients had stenoses in each branch of the ductal system (primary, secondary, and tertiary ducts). In 19% of patients, the main duct was of normal caliber despite the presence of stenosis in the more proximal ducts (secondary and tertiary ducts). Peripheral (proximal) duct dilation was characterized among those affected in patterns classified as destructive (34.6%), cavitary (26.9%), globular (11.5%), or punctate (11.5%). A statistically significant positive correlation (p = .0360) was identified between symptom duration and degree of main ductal stenosis.

CONCLUSION

Sialography may be useful to objectively assess the degree of parotid ductal damage in SS employing a newly proposed classification system. This assessment may assist clinicians in tailoring management to selectively include ductal dilation.

Dual-Source Dual-Energy CT in Submandibular Sialolithiasis: Reliability and Radiation Burden

OBJECTIVE. This study aims to compare the diagnostic accuracy of virtual unenhanced CT images derived from dual-source dual-energy contrast-enhanced CT with that of standard unenhanced CT images for evaluation of sialolithiasis. MATERIALS AND METHODS. All dual-energy CT studies of the neck performed during the preceding 5 years were reviewed for submandibular gland calculi. Only patients who had unenhanced CT and contrast-enhanced CT performed as part of the same evaluation were included in this study. This review yielded 30 patients. Virtual unenhanced CT images were derived from the dual-energy dataset and compared with the true unenhanced CT images by two separate radiologists who assessed the total number of calculi encountered, their location, the largest dimension, and the attenuation of the calculi. The radiation burden incurred for true unenhanced CT and virtual unenhanced CT and the total radiation burden were calculated. RESULTS. Our analysis revealed that measurements of stone size showed good interobserver agreement. The mean stone size was 7.9 ± 5.9 (SD) mm on virtual unenhanced CT and 8.4 ± 5.9 mm on true unenhanced CT (range, 2.0-31.8 mm); the difference was statistically insignificant. The mean stone attenuation differed considerably (p < 0.01) between the virtual and true unenhanced CT images (494.8 ± 187.5 HU and 924.4 ± 374.9 HU, respectively), but correlated well. The mean radiation dose for a dual-phase IV contrast-enhanced CT study was 23.13 mGy (volume CT dose index). The mean dose was 10.93 mGy for the true unenhanced CT phase, thereby suggesting a 47.25% reduction in administered radiation dose when a single-phase contrast-enhanced CT study with virtual unenhanced image reconstructions is performed. CONCLUSION. Virtual unenhanced CT images derived from dual-source dual-energy CT scans of the neck provide accurate assessment of sialolithiasis akin to that provided by conventional CT protocols but at only a fraction of the radiation dosage.

Radiocontrast Dye Extravasation During Sialography

Objective:

Evaluate the pathophysiology of contrast extravasation.

Methods:

Two hundred fifty-five sialograms at the University of Iowa from 2008 to 2016 were reviewed.

Results:

Twelve sialograms (4.7% of total) were identified with main ductal extravasation. In each case, ductal stenosis as a diagnosis was supported by clinical history and the finding of difficulty in advancing the cannula into the duct during sialography. In all but 1 case, extravasation occurred at the distal duct with no further imaging of the ductal system. Each of the 5 cases treated with sialendoscopy with or without gland resection confirmed stenosis. Ultrasound evaluation of 5 of the cases detected ductal dilation in 4 (80%). Six of 11 computed tomography scans done before the sialogram were interpreted as normal with indirect evidence for ductal stenosis (duct dilation) reported in only 1. All extravasations were associated with either stricture alone or stricture with stone (1 case).

Conclusion:

Radiocontrast extravasation from the main duct during sialography is highly associated with the presence of ductal stricture. In our experience, the inability to fill the ductal system with radiocontrast is a useful sialographic finding that correlated closely with anatomic abnormality rather than technical error. The frequent finding of extravasation of radiocontrast supports the use of water soluble contrast.

Comparison of the diagnostic performance of panoramic and occlusal radiographs in detecting submandibular sialoliths

Purpose

The aim of this study was to assess and compare the diagnostic performance of panoramic and occlusal radiographs in detecting submandibular sialoliths.

Materials and Methods

A total of 40 patients (20 cases and 20 controls) were included in this retrospective study. Cases were defined as subjects with a submandibular sialolith confirmed by computed tomography (CT), whereas controls did not have any submandibular calcifications. Three observers with different expertise levels assessed panoramic and occlusal radiographs of all subjects for the presence of sialoliths. Intraobserver and interobserver agreement were assessed using the kappa test. Sensitivity, specificity, accuracy, positive and negative predictive values, and the diagnostic odds ratio of panoramic and occlusal radiographs in screening for submandibular sialoliths were calculated for each observer.

Results

The sensitivity and specificity values for occlusal and panoramic radiographs all ranged from 80% to 100%. The lowest values of sensitivity and specificity observed among the observers were 82.6% and 80%, respectively (P=0.001). Intraobserver and interobserver agreement were higher for occlusal radiographs than for panoramic radiographs, although panoramic radiographs demonstrated a higher overall accuracy.

Conclusion

Both panoramic and occlusal radiographic techniques displayed satisfactory diagnostic performance and should be considered before using a CT scan to detect submandibular sialoliths.

Sialolithiasis in an Accessory Submandibular Gland Identified by Magnetic Resonance Sialography

BACKGROUND

Accessory submandibular gland is a very rare anatomical variant. There have been only 6 reported cases of this entity in the English literature, only 1 of which was identified using magnetic resonance imaging.

METHODS

We report the case of a 39-year-old female with symptoms of left submandibular sialoadenitis who was diagnosed of sialolithiasis within the left accessory submandibular gland by magnetic resonance sialography (MR-Si).

RESULTS

The calculus was palpated near the submandibular papilla and was extracted by an intraoral approach. One-year follow-up revealed no evidence of recurrence.

CONCLUSIONS

This is the first case reported to date in the English literature of a patient with sialolithiasis within an accessory submandibular gland diagnosed by MR-Si.