Validation of quantitative salivary gland scintigraphy in relation to the American–European concensus criteria for Sjögren’s syndrome

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.

Correlations between salivary gland scintigraphy and histopathologic data of salivary glands in patients with primary Sjogren's syndrome

OBJECTIVES

Our aim was to evaluate the association between salivary gland scintigraphy and the clinical parameters, including histological characteristics of salivary glands, in patients with primary Sjogren's syndrome (pSS).

METHODS

Forty-one pSS patients were included in the study. The patients who had received salivary gland scintigraphy and minor salivary gland biopsy were retrospectively analyzed. Salivary gland scintigraphy was interpreted via semi-quantitative methods obtained by calculating the peak uptake and washout of each gland using regions of interest. All specimens were examined by pathologists for focus scores and leukocyte common antigen (LCA) to determine the degree of inflammatory infiltration.

RESULTS

The mean age of pSS patients was 46.4 years, 82.9% were female, and the mean duration of symptoms was 2.5 years. The focus score was negatively correlated to the mean peak uptake (r = ‒0.396; p = 0.019), mean uptake (r = ‒0.388; p = 0.021), and mean percentage washout (r = ‒0.391; p = 0.02). In addition, the focus score and number of LCA positive cells per mm² were correlated with the clinical parameters including erythrocyte sedimentation rate, globulin, rheumatoid factor, unstimulated whole saliva, and stimulated whole saliva flow. The number of LCA positive cells per mm² was negatively correlated to leukocytes and hemoglobin.

CONCLUSION

Although the diagnostic role of salivary gland biopsy is widely accepted and features in the classification criteria of Sjogren's syndrome, salivary gland scintigraphy may be an acceptable alternative method especially if a non-invasive test is required.

Treatment Strategy for Chronic Obstructive Parotitis Related to Diabetes: A Retrospective Analysis of 12 Cases

Objectives: The aim of this study was to describe our experience in treating chronic obstructive parotitis (COP) related to diabetes.

Methods: Twelve patients with COP related to diabetes were selected for the study. A sialendoscope was introduced from the orifice to investigate the ductal wall and lumen. During the operation, chymotrypsin and gentamicin were injected. All patients were followed up for 6 months. Preoperative and postoperative visual analog scale (VAS) evaluations and salivary gland scintigraphy (SGS) examinations were applied to evaluate the therapeutic effect; differences were considered statistically significant at p < 0.05.

Results: A sialendoscope was successfully used under local anesthesia in all members of the cohort. As shown by the endoscope, mucus plugs were the most common feature. Some adhered tightly to the ductal wall. We also found ductal congestion in some cases. The postoperative VAS scores and SGS counts were both significantly lower than the preoperative values (p < 0.05).

Conclusion: Chymotrypsin administration during interventional sialendoscopy is significantly effective in the treatment of diabetes-related COP.

Recent Advances in Salivary Scintigraphic Evaluation of Salivary Gland Function

Saliva plays an important role in supporting upper gastrointestinal tract function and oral well-being. Salivary dysfunction mainly manifests with a decrease in salivary flow. Among varieties of quantitative methods, salivary scintigraphy is a relatively noninvasive, well-tolerated, reproducible, and objective approach for functional evaluation of salivary disorders, yet the lack of precise quantitative reference values and no standardized protocol limit its generalized utilization. In this article, we review the scintigraphic performance between the visual analysis and quantitative methods in predicting Sjögren’s syndrome and verify the potential aspects of the application in interpreting different disease entities and phases of functional salivary disorders.

The validity of salivary gland scintigraphy in Sjögren's syndrome diagnosis: comparison of visual and excretion fraction analyses

OBJECTIVES

The diagnostic validity of salivary gland scintigraphy in Sjögren's syndrome (SS) has not been conclusively defined. Whether a quantitative (excretion fraction) interpretation of scintigraphy is superior to a qualitative one (visual analysis) remains a matter of debate. We sought to determine whether the diagnostic discrimination of excretion fraction is higher compared to that obtained by visual analysis.

METHODS

Diagnostic test validity study that encompassed 137 suspected SS subjects who underwent scintigraphy for diagnostic purposes. Patients were diagnosed as SS and non-SS according to the rheumatologist's clinical judgment, and by using the American-European Consensus Group (AECG) and American College of Rheumatology (ACR) classification criteria. Visual analysis (normal vs. abnormal and Schall's classification grade) and excretion fraction scores were calculated. The diagnostic discrimination of these methods was compared through the area under the curve (AUC) analysis. Scintigraphy associations with SS clinical and laboratory features were assessed through multivariable regression analysis.

RESULTS

Schall's classification AUC reached statistical significance in its diagnostic discrimination for SS clinical judgment (0.704 [95%CI 0.597-0.811]) and AECG criteria (0.764 [95%CI 0.641-0.886]). Similarly, submandibular excretion fraction was associated with SS diagnosis based on ACR (0.737 [95%CI 0.546-0.931]) and AECG criteria (0.715 [95%CI 0.597-0.833]). However, AUC comparisons between qualitative and quantitative methods did not yield statistically significant values. Both interpretation modalities were associated with SS serological features. Moreover, excretion fraction was also associated with salivary gland biopsy.

CONCLUSIONS

SS diagnostic discrimination of excretion fraction is not superior to that obtained by qualitative visual analysis. Both qualitative and quantitative scintigraphy methods are associated with SS clinical and laboratory characteristics.

Quantitative evaluation of salivary gland scintigraphy in Sjögren's syndrome: comparison of diagnostic efficacy and relationship with pathological features of the salivary glands

OBJECTIVE

The value of salivary gland scintigraphy (SGS) in the evaluation of Sjögren's syndrome (SS) remains controversial. The aim of this study was to evaluate the diagnostic efficacy of quantitative SGS in patients with xerostomia and to assess the correlation between scintigraphic parameters and pathological features of salivary glands.

METHODS

Medical records of 165 patients with xerostomia who underwent [99mTc] pertechnetate SGS and labial biopsy were retrospectively reviewed. The maximum accumulation ratio (MAR), maximum secretion ratio (MSR), and time interval from stimulation to minimum count (T_min) of the parotid glands were calculated to quantify the glandular activity. Furthermore, pre-stimulatory oral activity index (PRI) and post-stimulatory oral activity index (POI) were calculated to quantify the oral activity.

RESULTS

All parameters except for T_min were significantly lower in patients with SS than in those without SS. Among the five SGS parameters, PRI showed the highest areas under the curve value (0.9005; p < 0.001), and PRI > 32.75 was associated with a sensitivity of 78.5% and specificity of 86.4% for the diagnosis of SS. A decrease in MAR, MSR, PRI, and POI and an increase in T_min correlate significantly with the histopathologic grade of labial gland biopsy and disease severity of SS. No significant differences in glandular parameters (MAR, MSR, and T_min) were found between the non-SS and early-stage SS groups.

CONCLUSION

Conventional scintigraphic parameters could be used as simple, reliable, and sensitive indicators for the early diagnosis of SS and determination of disease severity.