Current status of imaging of Sjogren's syndrome

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.

The anatomical pattern of ductal arborization in parotid glands using cone-beam computerized sialography

Cone-Beam Computed Tomography-Sialography (Sialo-CBCT) is used to demonstrate salivary ductal structure. This study aimed to conduct a volumetric analysis of the anatomical morphology of Normal-Appearing Glands (NAGs) in parotid sialo-CBCT. Our retrospective study included 14 parotid sialo-CBCT scans interpreted as NAGs in 11 patients with salivary gland impairment. The main duct length and width, as well as number and width of secondary and tertiary ducts were manually evaluated. We found that the main parotid duct showed an average width of 1.39 mm, 1.15 mm, and 0.98 mm, for the proximal, middle and distal thirds, respectively. The arborization pattern showed approximately 20% more tertiary (average number 11.1 ± 2.7) than secondary ducts (average number 9.0 ± 2.4) and approximately 8% narrower tertiary ducts (average width 0.65 ± 0.11 mm) compared to the secondary ducts (average width 0.77 ± 0.14 mm). Our anatomical analysis of NAGs in parotid sialo-CBCT demonstrated progressive narrowing of the main duct and increasing arborization and decreasing lumen size starting from the primary to the tertiary ducts. This is the most updated study regarding the anatomy of the parotid glands as demonstrated in sialo-CBCT. Our results may provide clinicians with the basic information for understanding aberration from normal morphology, as seen in salivary gland pathologies as well facilitate planning of treatment strategies, such as minimally invasive sialo-endoscopies, commonly practiced today.

A bibliometric analysis of primary Sjögren's syndrome-associated lymphoma from 1991 to 2022

Background

Patients with primary Sjögren's syndrome (pSS) take a higher risk of developing lymphoma, which is the most frequent cause of death in pSS. Based on this situation, the number of publications focusing on pSS-associated lymphoma has been growing. Nevertheless, the extent, range, and nature of available research in this field have not been systematically summarized. This study aimed to map the literature available on pSS-associated lymphoma and identify global hotspots and trends.

Methods

Papers on pSS and lymphoma published from 1991 to 2022 were searched from the Web of Science Core Collection. Microsoft Excel, SPSS Statistics, VOSviewer, and CiteSpace software were used to analyze and visualize the quantity and citations of publications, and the global research hotspots and trends of pSS-associated lymphoma.

Results

629 publications from 50 countries/regions and 538 institutions were included in this study. From 1991 to 2022, the cumulative publications steadily increased. The USA ranked first in the number of publications (n = 118, 18.76 %), followed by Italy (n = 94, 14.94 %) and France (n = 73, 11.61 %). Udine University (n = 29) and Salvatore De Vita (n = 39) were the most prolific affiliation and author, respectively. Claudio Vitali was the most frequently cited author (n = 335). In total, the most frequently occurring keywords were clustered into four well-defined groups. The first group of keywords pointed to the clinical assessment and treatment of pSS-associated lymphoma. The second group highlighted the pathogenesis. The third group identified the predictors and prognosis of pSS-associated Lymphoma, while the fourth group focused on interstitial lung disease and pulmonary lymphoma in patients with pSS. Currently, the hot keywords include consensus, disease activity, and pathogenesis. Ultrasonography, mucosa-associated lymphoid tissue (MALT) lymphoma, and epidemiology are the emerging research trends in pSS-associated lymphoma.

Conclusion

Research on pSS-associated lymphoma is burgeoning. Despite clinical assessment, treatment and pathogenesis, researchers also showed great interest in the predictors, prognosis, and pulmonary manifestations of pSS-associated lymphoma. Current research of pSS-associated lymphoma mainly focuses on consensus, disease activity, and pathogenesis, while the emerging research trends in pSS are pointing to ultrasonography, MALT lymphoma and epidemiology.

Quantitative Texture Analysis of Parotid Gland Ultrasound Images Yield Higher Correlation with Scintigraphy than Semiquantitative Scoring in Primary Sjögren's Syndrome Patients

Background

Ultrasound (US) can detect salivary gland abnormalities in primary Sjögren's syndrome (SS). This study aimed to compare the correlation among the semiquantitative US scores, texture features, and the quantitative salivary gland scintigraphy (SGS) results.

Methods

This retrospective study included 11 patients who were diagnosed with primary SS and underwent US examinations of the parotid glands and SGS simultaneously. We evaluated SGS quantitatively based on the calculation of maximum accumulation ratio (MAR) and stimulated excretion fraction (EF). The US findings were accessed through the semiquantitative Outcome Measures in Rheumatology scoring system and by gray-level co-occurrence matrix (GLCM) texture analysis. Spearman's rank correlation tests were performed.

Results

A significant moderate negative correlation was noted between the semiquantitative US score and MAR (rho = -0.57, P = 0.006), but not with EF (rho = -0.11, P = 0.613). The GLCM texture metrics, including contrast, dissimilarity, and homogeneity, were all determined to be significantly associated with both MAR and EF. The GLCM contrast correlated moderately to MAR (rho = -0.66, P = 0.001). The GLCM homogeneity highly correlated to EF (rho = 0.74, P < 0.001). The contrast and homogeneity can still discriminate the changes in MAR and EF in the subgroups with the same semiquantitative US scores.

Conclusion

US findings on parotid gland can correlate with SGS results when analyzed based on GLCM texture features. With the GLCM texture metrics, US appears to be an excellent imaging tool for the assessment of the parotid glands in primary SS patients.

Value of magnetic resonance imaging and sialography of the parotid gland for diagnosis of primary Sjögren syndrome

AIM

To evaluate the utility of magnetic resonance imaging (MRI) and magnetic resonance sialography (MRS) for diagnosis of primary Sjögren syndrome (pSS) singly or integrated with 2016 American College of Rheumatology (ACR)/European League Against Rheumatic Diseases (EULAR) classification criteria.

METHODS

The diagnostic efficiencies of MRI, MRS, and labial salivary gland biopsy (LSGB) were evaluated. The prediction model was established by multivariate analysis. Finally, performance of the ACR/EULAR criteria was evaluated after addition of MRI + MRS or replacement of original items by MRI + MRS.

RESULTS

The combined use of LSGB + MRI + MRS provided the greatest diagnostic value. MRI and MRS grade had positive correlations with disease duration and pathological grade of the labial gland (both P < 0.001). MRI and MRS grade had positive correlations with xerostomia severity and negative correlations with unstimulated salivary flow rate (both P < 0.001). The consistency of MRI grade and MRS grade in the diagnosis of parotid gland lesions was poor (κ = 0.253, P < 0.001). The diagnostic efficiency of our prediction model (AUC 0.906) was similar to that of criteria from the ACR/EULAR (AUC 0.930). Adding MRI + MRS to the ACR/EULAR criteria improved the sensitivity (92.3% vs 90.8%), whereas the specificity remained the same (88.9% vs 89.1%). Replacing LSGB by MRI + MRS in the ACR/EULAR criteria decreased both sensitivity and specificity (88.1% vs 90.8% and 86.4% vs 89.1%, respectively).

CONCLUSION

The combined application of MRI and MRS has ideal clinical application value in the diagnosis of early-stage pSS. Validity of the ACR/EULAR criteria remains high after incorporation of MRI + MRS.

Correlations of MR Sialographic Gradings with the Clinical Measures of Sjögren's Syndrome

OBJECTIVES

Sjögren syndrome (SS) features salivary gland architectural changes such as ductal deformities and fat deposition secondary to inflammatory cell infiltrates; however, the anatomical and pathophysiological correlations of SS remain to be determined. This study aimed to determine the correlations of imaging findings based on the magnetic resonance (MR) sialography with the clinical and laboratory aspects of SS patients.

METHODS

We evaluated the MR sialographic findings of two pairs of parotid glands (PGs) and submandibular glands (SMGs) from 41 SS patients. The distinct MR sialographic features were then compared with the clinical symptoms, biological (anti-SSA/Ro antibody positivity), histological (labial gland focus score), and functional (salivary flow and scintigraphy) data.

RESULTS

Ductal deformities such as sialectasis in the PG ducts were exclusively observed in SS, and fat replacement in SMGs was more distinct in patients with SS than in non-SS sicca patients. Of the 82 PGs and SMGs from 41 SS patients, the grade of sialectasis in PGs on MR sialographic images and fat stage in SMGs showed strong correlations with anti-SSA/Ro-positivity. PG sialectasis was found more frequently in patients with dry mouth and decreased salivary gland function. A significant correlation was found between fat deposition in PGs and SMGs and decreased salivary gland function.

CONCLUSION

These results suggest that MR sialography is a reliable, adjunctive anatomical and functional study to assess SS. Detail aspects of sialectasis and fat accumulation encountered on MR sialography in SS patients can help physicians assume the disease status in SS.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:307-316, 2023.

Impact of age on the diagnostic performance of unstimulated salivary flow rates and salivary gland ultrasound for primary Sjögren's syndrome

Background

Age-related changes and different patterns of salivary gland abnormalities according to age may affect the diagnostic performance of unstimulated salivary flow rate (USFR) and salivary gland ultrasound (SGUS) for primary Sjögren's syndrome (pSS). We aimed to evaluate the threshold and diagnostic performance of USFR and whether incorporating SGUS or replacing USFR with SGUS affects the performance of the ACR/EULAR criteria for pSS according to age.

Materials and methods

This medical chart review study included patients with suspected pSS who completed evaluations for pSS. Patients were classified based on age at pSS evaluation: elderly (≥65 years), middle-aged (40–64), and young (&lt; 40). The USFR's optimal thresholds were evaluated using the ROC curve. The diagnostic performances of the USFR and modified ACR/EULAR criteria were compared.

Results

In total, 239 pSS patients and 92 patients with idiopathic sicca syndrome were included. The cut-off of USFR ≤ 0.1 mL/min was irrelevant to age, demonstrating the best sensitivity (44.3–53.0%) and specificity (74.1–90.9%). SGUS had a significantly better AUC than USFR in the young (p &lt; 0.01) and middle-aged groups (p &lt; 0.01). The middle-aged group demonstrated better diagnostic performance of the ACR/EULAR criteria incorporating SGUS (AUC 0.957) (p &lt; 0.01) and criteria replacing USFR with SGUS (AUC 0.957) (p &lt; 0.001) compared to the original criteria (AUC 0.916). In the young and elderly groups, adding SGUS to the ACR/EULAR criteria or replacing USFR with SGUS did not significantly increase the AUC.

Conclusions

The thresholds of USFR ≤ 0.1 mL/min was optimal, irrespective of age. Using SGUS can improve diagnostic accuracy of ACR/EULAR criteria by supplementing the USFR, especially in middle-aged patients.

Imaging characteristics of Sjögren's syndrome

The current workup of Sjögren's syndrome is based on diagnostic criteria involving a combination of histology, immunology, ophthalmology, and salivary flow. Several modern imaging techniques provide complementary and additional information to diagnosis, staging, and surveillance. In this review article, we discuss the characteristic salivary imaging findings seen with the most commonly utilized imaging modalities. We also discuss imaging findings of the central nervous system disorders associated with Sjögren's syndrome, including the neuromyelitis optica spectrum disorder, and provide a differential diagnosis of alternative etiologies that can mimic Sjögren's syndrome.

The Diagnostic Value of MRI-Based Radiomic Analysis of Lacrimal Glands in Patients with Sjögren's Syndrome

This study aimed to assess the effectiveness of MRI-based texture features of the lacrimal glands (LG) in augmenting the imaging differentiation between primary Sjögren’s Syndrome (pSS) affected LG and healthy LG, as well as to emphasize the possible importance of radiomics in pSS early-imaging diagnosis. The MRI examinations of 23 patients diagnosed with pSS and 23 healthy controls were retrospectively included. Texture features of both LG were extracted from a coronal post-contrast T1-weighted sequence, using a dedicated software. The ability of texture features to discriminate between healthy and pSS lacrimal glands was performed through univariate, multivariate, and receiver operating characteristics analysis. Two quantitative textural analysis features, RunLengthNonUniformityNormalized (RLNonUN) and Maximum2DDiameterColumn (Max2DDC), were independent predictors of pSS-affected glands (p < 0.001). Their combined ability was able to identify pSS LG with 91.67% sensitivity and 83.33% specificity. MRI-based texture features have the potential to function as quantitative additional criteria that could increase the diagnostic accuracy of pSS-affected LG.

Sjögren syndrome: looking forward to the future

Primary Sjögren’s syndrome (pSS) is a heterogeneous disease characterised by a wide spectrum of manifestations that vary according to the different stages of the disease and among different subsets of patients. The aim of this qualitative literature review is to summarise the recent advances that have been reported in pSS, ranging from the early phases to the established disease and its complications. We analysed the diagnostic, prognostic, and management aspects of pSS, with a look into future clinical and research developments. The early phases of pSS, usually antedating diagnosis, allow us to investigate the pathophysiology and risk factors of the overt disease, thus allowing better and timely patient stratification. Salivary gland ultrasound (SGUS) is emerging as a valid complementary, or even alternative, tool for histopathology in the diagnosis of pSS, due to a standardised scoring system with good agreement and performance. Other promising innovations include the application of artificial intelligence to SGUS, ultrasound-guided core needle biopsy, and a wide array of novel diagnostic and prognostic biomarkers. Stratifying pSS patients through the integration of clinical, laboratory, imaging, and histopathological data; differentiating between activity-related and damage-related manifestations; and identifying patients at higher risk of lymphoma development are essential steps for an optimal management and individualised treatment approach. As new treatment options are emerging for both glandular and systemic manifestations, there is a need for a more reliable treatment response evaluation. pSS is a complex and heterogeneous disease, and many distinct aspects should be considered in the different stages of the disease and subsets of patients. In recent years, efforts have been made to improve our understanding of the disease, and certainly in the coming years, some of these novelties will become part of our routine clinical practice, thus improving the management of pSS patients.

Shear wave elastography as a potential additional diagnostic tool in primary Sjögren's syndrome: an observational study

The primary aim of this study was to verify if shear wave elastography can be used to evaluate salivary gland involvement in primary Sjögren's syndrome (pSS). The secondary objective was to establish an accurate cut-off value for parotid and submandibular salivary gland stiffness and to verify whether there are any distinctions among pSS patients with or without subjective mouth dryness. This prospective study included 45 patients with pSS (2016 ACR/EULAR classification criteria) and 108 healthy controls. All subjects underwent bilateral shear wave elastography of the parotid and submandibular salivary glands. Clinical data of pSS patients were collected and compared to elastography results. Patients with pSS had significantly higher shear wave elastography values for the parotid and submandibular salivary glands than the controls. There were no statistical differences in SWE values between patients with or without mouth dryness. The optimal cut-off value (mean value of 4 salivary glands shear wave elastography results) to distinguish patients with or without pSS was 13.19 kPa with sensitivity = 97.8% and specificity = 100.0%. It was, therefore, confirmed that shear wave elastography measurement of salivary glands has strong predictive ability in pSS detection (AUC 97.8%, 95% CI 93.4-100.0%). Shear wave elastography seems to be a promising, non-invasive and simple quantitative adjunct test to support the diagnosis of pSS with good sensitivity and specificity. More extensive prospective studies are needed to standardize a study protocol.

Comparison of salivary gland MRI and ultrasonography findings among patients with Sjögren's syndrome over a wide age range

Objectives

This retrospective study compared MRI and US findings among patients with SS over a wide age range.

Methods

Ninety patients with SS aged 8–84 years who had undergone both MRI and US examinations were divided into four groups according to age, as follows: <18 years (juvenile SS, JSS), 9 patients; 18–39 years, 12 patients; 40–69 years, 53 patients; >69 years, 16 patients. Imaging findings of parotid glands (PGs) and submandibular glands (SMGs) were compared among the four groups. Furthermore, the relationships within and between imaging findings and various clinical findings were examined.

Results

On MRI, patients with JSS commonly exhibited multiple high-intensity spots in the PGs on MR sialography and fat-suppressed T2-weighted imaging. With increasing SS group age, the frequencies and numbers of the high-intensity spots were lower. Fat areas on MRI and hyperechoic bands on US were rarely observed in the PGs and SMGs of patients with JSS, whereas they were more common in patients with adult SS. In addition, the presence of hyperechoic bands on US, the presence of fat areas on MRI, and decreased salivary flow were associated with one another.

Conclusion

Salivary gland imaging findings in patients with JSS were characterized by punctate sialectasis, whereas those findings in patients with adult SS were characterized by fatty degeneration. Distinct findings in patients with JSS and adult SS are likely to reflect differences in glandular lesion stage. MRI and US are presumably useful for evaluation of glandular lesion severity during follow-up.

Ultrasound and Bioptic Investigation of Patients with Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a chronic and heterogeneous disorder characterized by a wide spectrum of glandular and extra-glandular features. The hallmark of pSS is considered to be the immune-mediated involvement of the exocrine glands and B-cell hyperactivation. This leads pSS patients to an increased risk of developing lymphoproliferative diseases, and persistent (>2 months) major salivary gland enlargement is a well-known clinical sign of possible involvement by B cell lymphoma. Better stratification of the patients may improve understanding of the mechanism underlying the risk of lymphoproliferative disorder. Here, we summarize the role of different imaging techniques and a bioptic approach in pSS patients, focusing mainly on the role of salivary gland ultrasonography (SGUS) and a US-guided core needle biopsy (Us-guided CNB) as diagnostic and prognostic tools in pSS patients with persistent parotid swelling.