Real-time sonoelastography of salivary glands for diagnosis and functional assessment of primary Sjögren's syndrome

Does ultrasound elastography have a role as a diagnostic method for Sjögren's syndrome in the salivary glands? A systematic review

OBJECTIVE

This systematic review was performed to examine the usefulness of salivary gland ultrasound elastography (USE) as a diagnostic tool for Sjögren's syndrome (SjS).

METHODS

Electronic databases (MEDLINE, EMBASE, the Cochrane Library, and Web of Science: Science Citation Index) were searched to identify studies using USE to diagnose SjS from database inception to 15 July 2022. The primary outcome was improved diagnostic accuracy for SjS with the use of USE. Risk of bias and applicability concerns were assessed using the GRADE system, which is continuously developed by the GRADE Working Group.

RESULTS

Among 4550 screened studies, 24 full-text articles describing the applications of USE to diagnose SjS were reviewed. The overall risk of bias was determined to be low for 17 of the 24 articles, medium for 5, and high for 2. Articles comparing patients with SjS and healthy subjects reported high diagnostic accuracy of USE, with most results showed statistically significant differences (parotid glands: 15 of the 16 articles, submandibular glands: 11 of the 14 articles).

CONCLUSIONS

This systematic review suggests that the assessment of salivary glands using USE is a useful diagnostic tool for SjS.

The diagnostic performance of salivary gland ultrasound elastography in Sjögren's syndrome and sicca symptoms: a systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the diagnostic performance of ultrasound elastography (USE) in distinguishing primary Sjögren's syndrome (pSS) from healthy/disease controls.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases for published literature on USE for diagnosing pSS. Bivariate random effects models were used to calculate the pooled sensitivity and specificity of USE. To determine the factors influencing heterogeneity, meta-regression and subgroup analyses were performed to assess country, diagnostic criteria, imaging mechanisms, shear wave elastography techniques, measurement location, control group category, and patient age. Publication bias was assessed using the asymmetry of the Deeks funnel plot.

RESULTS

Fifteen articles covering 816 patients and 735 control participants were included. USE showed a pooled sensitivity of 0.80 (95% CI: 0.71-0.87) and specificity of 0.87 (95% CI: 0.78-0.92). Meta-regression and subgroup analyses revealed that shear wave elastography techniques, measurement location, and patient age were significant factors that affected study heterogeneity (p < 0.05). Elastography performs better in diagnosing patients aged ≤ 51 years compared to patients aged > 51 years. There was no significant publication bias.

CONCLUSION

USE demonstrates high accuracy in differentiating between pSS and healthy/disease control groups.

CLINICAL RELEVANCE STATEMENT

Ultrasound elastography, as a non-invasive and cost-effective technique, can be used to distinguish primary Sjögren's syndrome from disease/healthy control groups by measuring the stiffness of salivary glands.

KEY POINTS

• Ultrasound elastography is an acceptable technique for the diagnosis of primary Sjögren's syndrome. • The pooled sensitivity and specificity of ultrasound elastography for diagnosing primary Sjögren's syndrome were 0.80 and 0.87, respectively. • In patients aged ≤ 51 years with primary Sjögren's syndrome, ultrasound elastography showed good diagnostic performance.

Lacrimal gland ultrasonography and elastography as a diagnostic and activity tool for primary Sjögren's syndrome

OBJECTIVE

To investigate the effectiveness of 2-dimensional shear wave elastography (2D-SWE) in the assessment of lacrimal gland involvement in primary Sjögren's syndrome (pSS) and to determine the association between ultrasonographic findings and clinical activity measures.

METHOD

Forty-six patients who fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) classification criteria of pSS and 23 age and gender-matched healthy control subjects were enrolled. Clinical, laboratory and labial biopsy histopathologic characteristics of patients were recorded. Disease activity of pSS and severity of ocular dryness were evaluated with EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) and Ocular Surface Disease Index (OSDI), respectively. Parotid and lacrimal gland architectures were assessed by B-mode ultrasound and 2D-SWE techniques.

RESULTS

Mean shear wave elastography measurements, reflecting loss of elasticity, were remarkably higher in pSS patients compared to healthy subjects both in the lacrimal and parotid glands (8.99 ± 3.45 vs 3.68 ± 1.76 in lacrimal glands and 14.14 ± 4.39 vs 7.83 ± 1.69 in parotid glands, all P < 0.001). Shear wave elasticity of lacrimal glands was correlated with OSDI and ESSPRI scores (r = 0.69; P = 0.001 and r = 0.58; P = 0.001, respectively). A cut-off value of 4.6 kPa in the lacrimal gland elasticity discriminated pSS patients from healthy subjects with a sensitivity of 94% and specificity of 87%.

CONCLUSION

Results of our study suggest that lacrimal glands lose elasticity in patients with pSS and the assessment of elasticity with 2D-SWE might help to classify patients as having pSS. Further studies are needed to validate the diagnostic utility of lacrimal 2D-SWE by including diseases other than pSS.

World Workshop on Oral Medicine VIII: Development of a Core Outcome Set for Dry Mouth: A Systematic Review of Outcome Domains for Xerostomia

OBJECTIVE

The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth.

STUDY DESIGN

A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized.

RESULTS

From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains.

CONCLUSION

There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

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.

Recent Advances of Salivary Gland Biopsy in Sjögren's Syndrome

Sjögren's syndrome (SS) is a chronic, systemic, inflammatory autoimmune disease characterized by lymphocyte proliferation and progressive damage to exocrine glands. The diagnosis of SS is challenging due to its complicated clinical manifestations and non-specific signs. Salivary gland biopsy plays an important role in the diagnosis of SS, especially with anti-Sjögren's syndrome antigen A (SSA) and anti-SSB antibody negativity. Histopathology based on biopsy has clinical significance for disease stratification and prognosis evaluation, such as risk assessment for the development of non-Hodgkin's lymphoma. Furthermore, histopathological changes of salivary gland may be implicated in evaluating the efficacy of biological agents in SS. In this review, we summarize the histopathological features of salivary gland, the mechanism of histopathological changes and their clinical significance, as well as non-invasive imaging techniques of salivary glands as a potential alternative to salivary gland biopsy in SS.

Diagnostic accuracy of salivary gland ultrasound in Sjögren's syndrome: A systematic review and meta-analysis

BACKGROUND

To systematically review the diagnostic accuracy of salivary gland ultrasound in primary Sjögren's syndrome (pSS).

METHODS

PubMed, Embase, CINAHL, Cochrane Central and Scopus and ClinicalTrials.gov were searched to identify diagnostic or validation studies in patients with pSS meeting the diagnostic criteria. A diagnostic test meta-analysis was performed using a bivariate model to calculate the pooled sensitivity, specificity, positive/negative likelihood ratios, and the diagnostic odds ratio. Meta-regression analyses were done for several pSS covariates.

RESULTS

Sixty-five studies met our criteria for the qualitative review. Fifty-four studies with a total of 6087 patients were included in the meta-analysis. Pooled sensitivity for salivary gland ultrasound was 80% [95% confidence interval (CI): 77-83%; I 2 = 78%], and specificity was 90% (95% CI: 87-92%; I 2 = 76%). The pooled positive and negative likelihood ratios were 8 (95% CI: 6.4-10) and 0.22 (95% CI: 0.19-0.25), respectively. The corresponding pooled diagnostic odds ratio (DOR) was 37 (95% CI: 28-48). Separate meta-regression models resulted in similar diagnostic estimates: (a) adjusted for mean age: sensitivity 81% (95% CI:77-84%; I 2 = 99%) and specificity 90% (95% CI: 87-93%; I2 = 99%); (b) adjusted for mean disease duration, sensitivity 79% (95% CI:72-84%; I 2 = 99%), and specificity 90% (89-94%; I 2 = 99%). The diagnostic estimates were robust to sensitivity analyses by quality criteria, pSS diagnostic criteria and ultrasound scoring systems.

CONCLUSION

Salivary gland ultrasound is a valuable modality for the diagnosis of Sjögren's syndrome. It is plausible that salivary gland ultrasound can be used as an important criterion for the diagnosis of pSS.

Current status of imaging of Sjogren's syndrome

Primary Sjögren's syndrome (pSS) is an autoimmune disease, which involves salivary glands (SG) and extra glandular organs. Today, Sjögren's patients' diagnosis is based on classification criteria taking into account five objective tests, including histology, immunology, two ophthalmological tests, and salivary flow evaluation. To date, the challenge is to find the right imaging tool for diagnosis, follow up, and prognosis of pSS. The objective of this review is to describe as to what are these imaging modalities and particularly the place and validity of salivary glands ultrasonography (SGUS) in the diagnosis and follow-up strategy of patients with suspected pSS. Moreover, new noninvasive tools are emerging, including elastography, a new ultrasonography technique that provides an estimate of tissue elasticity, MRI, MR sialography, and ¹⁸ fluorodeoxyglucose-positron emission tomography. Although new imaging opportunities are available, SGUS should be the first-line choice in pSS because of its accessibility, feasibility over time, and sensitivity to change.

Combining surface-enhanced Raman scattering (SERS) of saliva and two-dimensional shear wave elastography (2D-SWE) of the parotid glands in the diagnosis of Sjögren's syndrome

In this study, we combine the molecular structural information gained by SERS of saliva samples with the morphological data given by two-dimensional shear wave elastography (2D-SWE) (SuperSonic Imagine, Aixplorer) of parotid glands in the case of n = 31 patients with Sjögren's syndrome (SjS) and n = 22 controls, with the aim to discriminate between the two groups. The overall classification accuracy yielded by a hybrid principal component analysis-linear discriminant analysis (PCA-LDA) model based on both SERS and elastography (81%) was superior to that yielded by SERS spectra alone (75%) and elastography data alone (71%). This preliminary study is the first report on the use of 2D-SWE of parotid glands for the diagnosis of SjS as well as the first to describe the diagnosis of SjS based on the SERS spectra of dried saliva samples, the results suggesting that the strategy of combining the two methods could improve the diagnosis of SjS.

Sonographic Features of Salivary Glands in Sjögren's Syndrome and its Mimics

PURPOSE OF REVIEW

For 30 years, ultrasound has been investigated as a means to evaluate salivary gland abnormalities in patients with autoimmune disease. We aim to review the test characteristics of ultrasound for diagnosing Sjögren's syndrome, the scoring systems used for this purpose, and the ultrasound similarities and differences between Sjögren's syndrome and some of its potential salivary gland mimics.

RECENT FINDINGS

Hypo/anechoic glandular lesions are the major ultrasound characteristic found in Sjögren's syndrome. Most studies have reported such ultrasound abnormalities to have a sensitivity and specificity in the range of 65-85% and 85-95%, respectively, as well as a positive likelihood ratio between 4 and 12. However, similar findings can also be seen in sarcoidosis, amyloidosis, IgG4-related disease, HIV, and lymphoma. A "nodal" pattern of involvement or the ultrasound artifact of "through transmission" can help distinguish some of these mimics from Sjogren's syndrome. Ultrasound can substantially influence the diagnosis of Sjögren's syndrome.

Shear wave elastography as a new method to identify parotid lymphoma in primary Sjögren Syndrome patients: an observational study

Parotid non-Hodgkin lymphoma (NHL) in primary Sjögren syndrome (pSS) has no specific biomarker for diagnosis. Salivary glands ultrasound (US) is largely used, but its contribution in detecting parotid NHL has not been established. The aim of our study was to determine the added value of bidimensional shear wave elastography (2D-SWE) in pSS diagnosis and to determine its accuracy in identifying parotid NHL. Grey-scale US (GSUS) and 2D-SWE of salivary glands were performed in 35 patients with pSS and 35 healthy controls. The GSUS scores were calculated and the mean of three SWE consecutive measurements was used to appreciate the gland stiffness. SWE increase the diagnostic rate at a cut-off of 6.45 kPa (from 88.6 to 94.2%, p < 0.001) only if applied in patients with insufficient GSUS criteria for pSS diagnosis. The parotid glands with NHL (8 patients, all mucosa-associated lymphoid tissue type) had hyperechoic bands in more than half of the glandular parenchyma (in 68.75% of the glands), large hypoechoic area > 20 mm (all glands), traced gland area over 5 cm² (all glands), parotid US score greater than 13 (in 68.75% of the glands), and high stiffness (elasticity modulus 13.9 ± 4.08 vs 6.32 ± 2.24) (all p < 0.001). These findings give high sensitivity (92.3%), specificity (100%), and positive (100%) and negative predictive values (98.3%) for NHL identification. The rest of GSUS findings did not correlate with the classic risk factors for lymphoma development (all p > 0.05). 2D-SWE had added value for pSS diagnosis in cases where GSUS aspect is normal or nonspecific. The higher stiffness of parotid NHL can be used for early diagnosis, biopsy guidance, and, possible, for treatment monitoring.

Usefulness of a deep learning system for diagnosing Sjögren's syndrome using ultrasonography images

OBJECTIVES

We evaluated the diagnostic performance of a deep learning system for the detection of Sjögren's syndrome (SjS) in ultrasonography (US) images, and compared it with the performance of inexperienced radiologists.

METHODS

100 patients with a confirmed diagnosis of SjS according to both the Japanese criteria and American-European Consensus Group criteria and 100 non-SjS patients that had a dry mouth and suspected SjS but were definitively diagnosed as non-SjS were enrolled in this study. All the patients underwent US scans of both the parotid glands (PG) and submandibular glands (SMG). The training group consisted of 80 SjS patients and 80 non-SjS patients, whereas the test group consisted of 20 SjS patients and 20 non-SjS patients for deep learning analysis. The performance of the deep learning system for diagnosing SjS from the US images was compared with the diagnoses made by three inexperienced radiologists.

RESULTS

The accuracy, sensitivity and specificity of the deep learning system for the PG were 89.5, 90.0 and 89.0%, respectively, and those for the inexperienced radiologists were 76.7, 67.0 and 86.3%, respectively. The deep learning system results for the SMG were 84.0, 81.0 and 87.0%, respectively, and those for the inexperienced radiologists were 72.0, 78.0 and 66.0%, respectively. The AUC for the inexperienced radiologists was significantly different from that of the deep learning system.

CONCLUSIONS

The deep learning system had a high diagnostic ability for SjS. This suggests that deep learning could be used for diagnostic support when interpreting US images.

Imaging methods in primary Sjögren's syndrome as potential tools of disease diagnostics and monitoring

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that affects exocrine glands, especially salivary and lacrimal glands, leading to their progressive destruction. With highly differentiated clinical course the approach to the definition of pSS is constantly evolving and the pSS classification criteria have been modified over the past years. In the past sialography and scintigraphy were frequently used in pSS diagnostics. Recently no imaging method has been included in the pSS classification criteria. That raises the question about the benefits of using novel imaging techniques such as ultrasonography, elastography and magnetic resonance imaging to diagnose and monitor pSS patients. The purpose of this review is to evaluate the advantages and limitations of widely used imaging methods in pSS and their possible future development.

Strain and shear wave ultrasound elastography in evaluation of chronic inflammatory disorders of major salivary glands

OBJECTIVE

The aim of this study was to assess chronic inflammatory conditions of major salivary glands by ultrasound elastography.

METHODS

21 patients with chronic inflammatory conditions of major salivary glands and 21 healthy adult volunteers were included in this study. All participants underwent B-mode sonography and ultrasound elastography. The diagnostic performance of strain ratio and shear wave velocity was evaluated by sensitivity and specificity at the optimum cutoff point and the area under the receiver operating characteristic curve.

RESULTS

Cases showed statistically significant higher median strain ratio of parotid and submandibular gland than control group (p-value = 0.001). Total cases showed statistically significant higher median scores than control group (p-value < 0.001). At cut-off value of (1.13); diagnostic accuracy, sensitivity and specificity were 97.6, 95.2 and 100% respectively with AUROC 0.954 and confidence interval: 0.840-0.995. Cases showed statistically significant higher median shear wave velocity of parotid gland than control group (p-value = 0.022), with no statistically significant difference in submandibular gland in the two groups (p-value = 0.216). Total cases showed statistically significant higher median scores than control group (p-value < 0.001). At cut-off value of (23.5), diagnostic accuracy was 78.6% with a sensitivity of 81% and specificity of 76.2% with 0.819 AUROC and onfidence interval :0.669-0.920.

CONCLUSION

Our initial experience suggests that elastography may be potentially useful for diagnosis of chronic inflammatory conditions of the major salivary glands. This conclusion needs to be further validated large sample studies.

Clinical ultrasonography in systemic autoimmune diseases

Clinical ultrasonography should be considered a complementary examination that can change clinical practice, as well as a tool to add to the medical history. Systemic autoimmune diseases (SAD) can involve numerous structures and organs. Ultrasonography has broad applied utility in detecting complications such as the presence of free intraabdominal, pleural and pericardial fluid in polyserositis, left ventricular systolic dysfunction in myocarditis and deep vein thrombosis in antiphospholipid syndrome. Specifically for SAD, ultrasonography helps examine the salivary glands in Sjögren's syndrome, determines the presence of the halo sign in giant cell arteritis and the presence of tendon or joint inflammation, quantifies pulmonary hypertension in scleroderma and assesses the presence of interstitial pulmonary disease in dermatomyositis. Clinical ultrasonography performed by internists is therefore an extremely useful technique in the diagnosis and follow-up of patients with SAD.

Latest Advances in Ultrasound Assessment of Salivary Glands in Sjögren Syndrome

OBJECTIVE

There are different imaging techniques to assess the parotid glands (i.e., sialography, salivary gland scintigraphy) in patients with Sjögren syndrome (SS). However, their use is limited by the invasive character or high cost. Ultrasound (US) is gaining interest by rheumatologists as a complementary diagnostic tool for SS. To date, there is an increasing body of evidence supporting its sensitivity in the assessment of salivary glands in SS. The aim of our study was to analyze the potential role of US as a diagnostic and prognostic tool in SS and to discuss existing evidence to support its application use.

METHODS

A systematic search was performed in the electronic database PubMed, using the following search terms: (salivary glands OR parotid glands OR submandibular glands) AND Sjögren's syndrome AND (ultrasonography OR ultrasound OR sonography). Titles, abstracts, and full reports were systematically screened.

RESULTS

The results of the studies analyzed in this review show encouraging results in terms of accuracy, validity, and diagnostic value, which leads us to believe that in the future US could become the reference imaging tool to assess SS. The studies include a small cohort of patients, and there is no standardized approach in terms of US techniques for the assessment of salivary glands.

CONCLUSIONS

Ultrasound of major salivary glands is a useful tool for diagnosis, prognostic evaluation, and response to treatment in SS. The use of this imaging technology is still under development, and more multicentric studies are needed to validate this tool.

Radiomics-Based Assessment of Primary Sjögren's Syndrome From Salivary Gland Ultrasonography Images

Salivary gland ultrasonography (SGUS) has shown good potential in the diagnosis of primary Sjögren's syndrome (pSS). However, a series of international studies have reported needs for improvements of the existing pSS scoring procedures in terms of inter/intra observer reliability before being established as standardized diagnostic tools. The present study aims to solve this problem by employing radiomics features and artificial intelligence (AI) algorithms to make the pSS scoring more objective and faster compared to human expert scoring. The assessment of AI algorithms was performed on a two-centric cohort, which included 600 SGUS images (150 patients) annotated using the original SGUS scoring system proposed in 1992 for pSS. For each image, we extracted 907 histogram-based and descriptive statistics features from segmented salivary glands. Optimal feature subsets were found using the genetic algorithm based wrapper approach. Among the considered algorithms (seven classifiers and five regressors), the best preforming was the multilayer perceptron (MLP) classifier (κ = 0.7). The MLP over-performed average score achieved by the clinicians (κ = 0.67) by the considerable margin, whereas its reliability was on the level of human intra-observer variability (κ = 0.71). The presented findings indicate that the continuously increasing HarmonicSS cohort will enable further advancements in AI-based pSS scoring methods by SGUS. In turn, this may establish SGUS as an effective noninvasive pSS diagnostic tool, with the final goal to supplement current diagnostic tests.

New applications of sonoelastography in rheumatology: where are we now?

Ultrasound elastography (UE) is a non-invasive imaging method that allows the assessment of tissue elastic property. Different UE techniques are currently available (i.e. strain UE and acoustic radiation force impulse UE), with several potential clinical applications. Recent studies investigated the role of UE in two systemic rheumatic diseases and psoriasis. This research added interesting information to the already known applications of UE in the assessment of tendinopathies. In SS, acoustic radiation force impulse UE has shown a potential role in the diagnosis of the disease, with lower sensitivity than and similar specificity to salivary gland histology. In SSc, a potential use of UE in screening pre-clinical disease has been reported. In psoriasis, the use of strain UE in evaluating treatment response has been highlighted. UE is a promising tool in rheumatology, with a potential role in the evaluation of various tissues and pathologies.

The Role of Real-Time Tissue Elastography and Gray-Scale Ultrasound Histogram Analysis in the Diagnosis of Patients With Sjögren's Syndrome

Objectives

This study aims to evaluate gray-scale histogram analysis of B-mode ultrasound (US) images and US elastographic features of the parotid glands in patients with Sjögren's syndrome (SS) and to explore relationships with the ultrasonographic and disease activity scores in the light of histopathological findings.

Patients and methods

A total of 57 consecutive female patients (mean age 47.9±10.4 years; range 25 to 76 years) with a diagnosis of SS and 48 healthy female individuals (mean age 51.1±10.8 years; range 20 to 70 years) underwent parotid ultrasonography and real-time tissue elastography imaging. Quantitative measurements of gray-scale US images were performed using the histogram software of the scanner. The histogram ratios of the parotid glands from both sides were obtained (histogram ratio; mean gray-scale histogram parotid/mean gray-scale histogram fat). Strain ratio (SR; ratio of fat to gland parenchyma) was calculated from the color-coded images. Subjective B-mode US scoring of electronically recorded gray- scale US images was performed by two radiologists independently for intra- and inter-observer agreement. Subjective assessments, quantitative measurements, and clinical parameters were compared.

Results

The SR of the patient group (1.4±0.8 right side, 1.5±0.9 left side) was significantly higher than that of the control group (1.0±0.3 right side, 1.1±0.3 left side) (p<0.05). The gray-scale histogram ratio of the patient group (1.3±0.5 right side, 1.4±0.9 left side) was lower than that of the control group (1.8±0.7 right side, 1.9±0.7 left side) (p<0.05). Receiver-operating-characteristics curve yielded 66% sensitivity for both sides and 50% and 52% specificity for the right and left sides, respectively, for a cut-off SR of 1.02; 76% and 86% sensitivity for the right and left sides, respectively, and 63% specificity for both sides for a cut-off histogram ratio of 1.35. The quantitative histogram ratio method had a higher positivity rate for the diagnosis of abnormal parotid glands than subjective assessments of US images.

Conclusion

Sonoelastography and gray-scale histogram analysis of the parotid glands may be used as auxiliary tools to detect parotid gland sonographic abnormalities in patients with SS.

Salivary gland ultrasonography in primary Sjögren's syndrome: opportunities and challenges

Salivary gland ultrasonography (SGUS) has an established role in detecting typical structural gland abnormalities in primary Sjögren's Syndrome (pSS). SGUS might be included in pSS classification and could be used as a prognostic and follow-up biomarker, but for this purpose additional efforts, new techniques and larger cohort studies are needed. HarmonicSS, an ongoing Horizon, EU-supported project in pSS, will apply artificial intelligence to SGUS in pSS. Many questions are still unresolved and challenging, but data collected up to now underscore the concept that SGUS will be an important tool for the study of pSS in the near future.

Ultrasound elastography in assessment of salivary glands involvement in primary Sjögren's syndrome

OBJECTIVE

Our study aimed to assess the pathological sonoelastographic changes in the major salivary glands and to demonstrate the diagnostic effectiveness of Sonoelastography as an additional method to US in Sjögren's syndrome.

METHODS

Fifty eight patients with primary Sjögren's syndrome (pSS) were selected according to the American-European Consensus Group Classification criteria. Twenty five healthy volunteers involved in this study. All patients were evaluated with B-mode and elastography by using Hitachi EUB 7500 digital ultrasound equipment. All subjects were female. The sonoelastography examination, which allowed us to assess the elasticity of the parenchyma, was performed and strain ratios were measured by comparing with the adjacent tissues.

RESULTS

Statistically significant differences were found between the pSS and control groups for the elastographic scores and strain ratios (p < 0.001). The highest sensitivity and specificity levels were obtained when the strain ratio cut-off value was taken as 1.55 for the submandibular gland and 2.45 for the parotid gland (sensitivity and specificity were 83% and 88% respectively for the submandibular gland and 83% and 92% respectively for the parotid gland). However, no statistically significant differences were found between the disease duration and the elasticity scores or strain ratios in pSS group (p > 0.05).

CONCLUSION

US examination is an efficient method to assess major salivary gland involvement in the diagnosis of pSS. Sonoelastography is a modality which can contribute to the diagnosis by improving specificity in the differential diagnosis of pSS. Strain ratio measurement, which is a semi-quantitative method, increases the diagnostic effectiveness by providing high sensitivity, specificity, and negative predictive values.

Elastographic ultrasound: an additional image tool in Sjögren's syndrome

AIM

To evaluate the stiffness of parotid and submandibular glands using elastography ultrasound and to correlate it with B-mode ultrasonographical, clinical and serological features, salivary profibrotic and inflammatory chemokines, and salivary gland fibrosis.

METHODS

We performed B-mode and elastography ultrasound of major salivary glands of 26 patients with primary Sjögren's syndrome. We registered the shear wave velocity (SWV) and correlated it with the morphologic ultrasonographic changes assessed by the Hocevar scale. We assessed the European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI), EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), non-stimulated whole salivary flow rate (NSWSF), C3 and C4 levels, anti-Ro/La antibodies, salivary inflammatory (C-X-C motif ligand 13 [CXCL13], CXCL10, CXCL8, C-C motif ligand 2 [CCL2], interleukin 10 [IL-10] and IL-6) and pro-fibrotic (CXCL14, CCL28, tumor necrosis factor-related apoptosis-inducing ligand and transforming growth factor β) chemokines and cytokines and evaluated the presence of fibrosis in the minor salivary gland.

RESULTS

Ninety-two percent of patients were women; mean age was 51.1 ± 11 years; median disease duration was 6.1 years; 92.3% had oral symptoms and 26.9% fibrosis. The median B-mode score was 22.2 points and the median SWV 2.5 m/s (τ = 0.53, P = 0.001). The SWV correlated with the NSWSF (τ = -0.53, P = 0.001), ESSDAI (τ = 0.31, P = 0.03), glandular ESDDAI domain (τ = 0.36, P = 0.02), C4 levels (τ = -0.32, P = 0.04), salivary CXCL13 (τ = 0.29, P = 0.03) and CXCL10 (τ = 0.30, P = 0.003), but not with age and fibrosis.

CONCLUSION

WV correlated with the B-mode ultrasound score, systemic and glandular activity and in a large degree with CXCL10, an inflammatory chemokine, but not with fibrosis. An increased SWV might represent chronic glandular inflammation rather than fibrotic changes in these patients.

Virtual Touch Quantification of the Salivary Glands for Diagnosis of Primary Sjögren Syndrome

OBJECTIVES

To investigate the value of salivary gland stiffness measured by Virtual Touch quantification (VTQ; Siemens Medical Solutions, Erlangen, Germany) for assessment of primary Sjögren syndrome.

METHODS

Fifty-four patients with primary Sjögren syndrome, 35 patients without primary Sjögren syndrome (patients with dry mouth and dry eye symptoms), and 52 healthy control volunteers were included in this study. Patients with primary Sjögren syndrome were classified as early or advanced stage by labial gland biopsies. All participants underwent B-mode sonography, on which the salivary glands (parotid and submandibular) were identified and VTQ measurements of shear wave velocity (SWV) were obtained. The diagnostic performance of SWV was evaluated by sensitivity and specificity at the optimum cutoff point and the area under the receiver operating characteristic curve.

RESULTS

For submandibular glands, the mean SWV ± SD values were 2.25 ± 0.34 m/s in patients with early-stage primary Sjögren, 1.84 ± 0.20 m/s in patients without primary Sjögren syndrome, and 1.82 ± 0.27 m/s in healthy controls (P< .001). With cutoff values of 2.15 and 2.10 m/s to separate patients with early-stage primary Sjögren syndrome from those without Sjögren syndrome and healthy controls, the sensitivity and specificity were 77.1% and 85.4% and 79.2% and 83.9%, respectively. For parotid glands, the SWV values were 2.78 ± 0.82 m/s in patients with early-stage primary Sjögren syndrome, 1.93 ± 0.33 m/s, in patients without primary Sjögren syndrome, and 1.85 ± 0.31 m/s in healthy controls (P < .001). With cutoff values of 2.18 and 2.10 m/s to separate patients with early-stage primary Sjögren syndrome from those without Sjögren syndrome and healthy controls, the sensitivity and specificity were 89.3 % and 75.3% and 91.4% and 80.0%.

CONCLUSIONS

The VTQ technique might be a useful noninvasive strategy for assessment of salivary glands in the early stage of primary Sjögren syndrome.

Assessment of the Stiffness of Major Salivary Glands in Primary Sjögren's Syndrome through Quantitative Acoustic Radiation Force Impulse Imaging

The purpose of the study described here was to evaluate salivary gland stiffness in primary Sjögren's syndrome (pSS) via acoustic radiation force impulse imaging, including Virtual Touch tissue quantification (VTQ) and Virtual Touch tissue imaging quantification (VTIQ). Twenty-one patients with pSS and 11 healthy patients were included, and the paired parotid and submandibular glands of all of the patients were examined using VTQ and VTIQ. Differences between the two groups were compared with independent and paired t-tests. The VTQ value for the parotid in the pSS group was significantly higher than that obtained for the control group (1.33 ± 0.22 and 1.18 ± 0.04 m/s, respectively, p < 0.01). The VTIQ values for the parotid and submandibular gland were both significantly higher in the pSS group than in the control group (p < 0.05). In the pSS group, a positive correlation was observed between the VTQ and VTIQ results for the parotid and submandibular glands. In summary, the stiffness of the major salivary glands in patients with pSS was increased compared with that of patients with normal glands. This finding indicates that VTQ and VTIQ imaging may be valuable adjuncts to gray-scale ultrasonography for the clinical diagnosis of pSS.

[Clinical usefulness of salivary gland ultrasonography in Sjögren's syndrome: Where are we now?]

Salivary gland ultrasonography is a simple, noninvasive and inexpensive procedure, which provides valuable information for the diagnosis of primary Sjögren's syndrome (pSS). The main sonographic characteristic of the major salivary glands (parotid and submandibular) in pSS patients is the heterogeneity of the parenchyma, with the appearance of hypoechoic areas. Numerous studies published over the past 20 years report a sensitivity of 70% and a specificity of more than 90% for the diagnosis of pSS. Before the widespread use of this procedure in daily practice and its integration into classification criteria of the disease, it has yet to be validated in terms of reproducibility and a consensus score should be established. This work is being conducted by an international group of experts. Other ultrasound techniques such as elastography could also be of interest to objectively quantify changes in the glandular tissue that occur during the disease.