The role of salivary gland elastosonography in Sjögren's syndrome: preliminary results

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.

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.

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.

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.

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.

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.

Shear Wave Sonoelastography Findings of Testicles in Chronic Kidney Disease Patients Who Undergo Hemodialysis

OBJECTIVE

Chronic kidney disease (CKD) is known to cause significant deterioration in the function of the testicles and sexual dysfunction in male patients who undergo hemodialysis. The aim of this study was to show the changes in the testicles that occur as a result of hypogonadism secondary to CKD and to analyze the elasticity of the parenchyma by shear wave sonoelastography.

MATERIALS AND METHODS

In our study we included 28 male patients who undergo dialysis three times per week and 25 healthy volunteers. Firstly, B-mode ultrasonographic evaluation was performed in both testicles for structural analysis and to detect the presence of focal lesions. Afterward, the stiffness of the parenchyma was measured in kilopascals by shear wave sonoelastography.

RESULTS

The CKD group had lower right, left, and mean testicular volumes (p<0.001). The CKD group also displayed greater right, left, and mean testicular parenchymal stiffness (p<0.001).

CONCLUSION

CKD patients who undergo hemodialysis demonstrated significant changes in testicular size and stiffness in comparison to healthy volunteers.