Magnetic resonance imaging and magnetic resonance sialography of parotid glands in primary Sjogren's syndrome

Three Signs to Help Detect Sjögren's Syndrome: Incidental Findings on Magnetic Resonance Imaging and Computed Tomography

This study aimed to retrospectively investigate the prevalence of Sjögren's syndrome (SS) among patients with ranulas, parotid cysts, or parotid calcifications; identify the characteristic magnetic resonance imaging (MRI) or computed tomography (CT) findings of the lesions associated with SS; and compare the SS disease stages among SS patients with the three lesion types. A total of 228 patients with the lesions were classified into SS, possible SS, and non-SS groups. The prevalence of SS among patients with ranulas, parotid cysts, or parotid calcifications was 16%, 24%, and 40%, and the rates of either SS or possible SS were 25%, 41%, and 64%, respectively. SS was associated with (i) ranulas: ≤17 mm; (ii) parotid cysts: bilateral and multiple; and (iii) parotid calcifications: in females, bilateral, multiple, parenchymal, and no coexisting calcifications in other tissues. SS patients with ranulas were significantly younger and had lower submandibular gland stage scores on MRI/CT than those with other lesions. Additionally, in 58% and 15% of SS patients with ranulas and parotid calcifications, respectively, detection of the lesions led to the diagnosis of primary SS. Therefore, recognizing the prevalence of SS among patients with these lesions and the findings associated with SS can help detect undiagnosed SS.

Radiomic Features Associated with Lymphoma Development in the Parotid Glands of Patients with Primary Sjögren's Syndrome

Non-Hodgkin Lymphoma (NHL) represents a severe complication and the main cause of morbidity in patients with primary Sjögren's syndrome (pSS). This study aimed to assess the role of textural analysis (TA) in revealing lymphoma-associated imaging parameters in the parotid gland (PG) parenchyma of patients with pSS. This retrospective study included a total of 36 patients (54.93 ± 13.34 years old; 91.6% females) diagnosed with pSS according to the American College of Rheumatology and the European League Against Rheumatism criteria (24 subjects with pSS and no lymphomatous proliferation; 12 subjects with pSS and NHL development in the PG, confirmed by the histopathological analysis). All subjects underwent MR scanning between January 2018 and October 2022. The coronal STIR PROPELLER sequence was employed to segment PG and perform TA using the MaZda5 software. A total of 65 PGs underwent segmentation and texture feature extraction (48 PGs were included in the pSS control group, and 17 PGs were included in the pSS NHL group). Following parameter reduction techniques, univariate analysis, multivariate regression, and receiver operating characteristics (ROC) analysis, the following TA parameters proved to be independently associated with NHL development in pSS: CH4S6_Sum_Variance and CV4S6_Inverse_Difference_Moment, with an area under ROC of 0.800 and 0.875, respectively. The radiomic model (resulting by combining the two previously independent TA features), presented 94.12% sensitivity and 85.42% specificity in differentiating between the two studied groups, reaching the highest area under ROC of 0.931 for the chosen cutoff value of 1.556. This study suggests the potential role of radiomics in revealing new imaging biomarkers that might serve as useful predictors for lymphoma development in patients with pSS. Further research on multicentric cohorts is warranted to confirm the obtained results and the added benefit of TA in risk stratification for patients with pSS.

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.

Comparative Study of Multiple High-Signal-Intensity Spots on 3D and 2D Magnetic Resonance Sialography for Patients with Sjögren's Syndrome

We investigated the sensitivities of 2-dimensional (2D) magnetic resonance sialography (MR-S) and unilateral sagittal and axial 3-dimensional (3D) MR-S using a surface coil and their combination in diagnosing patients with Sjögren's syndrome (SS). We retrospectively analyzed the 3D and 2D MR-S results of 78 patients with SS. We evaluated the sensitivities of multiple high-signal-intensity spots and staging on MR sialograms and analyzed the efficient imaging methods and cross section for diagnosing patients with SS. The sensitivities of MR-S for detecting abnormal findings (i.e., MR-S stage 1 or higher) were as follows: 65 cases (83.3% [95% confidence interval (CI): 73.2-90.8]) for unilateral sagittal 3D MR-S; 62 cases (79.4% [95% CI: 68.8-87.8]) for axial 3D MR-S; 66 cases (84.6% [95% CI: 74.7-91.8]) for combined unilateral sagittal and axial 3D MR-S; and 32 cases (41.0% [95% CI: 30.0-52.7]) for bilateral sagittal 2D MR-S. The ratio of the abnormal finding of MR-S was tested using the two-tailed Fisher's exact test. Unilateral sagittal, axial, and combined unilateral sagittal and axial 3D MR-S showed significantly higher sensitivity than bilateral sagittal 2D MR-S, respectively (P < 0.001). Most cases upstaged by 3D MR-S were those positive (stage 1 or higher) among the stage 0 cases detected by 2D MR-S. Axial 3D MR-S, compared with 2D MR-S, understaged four cases, which was due to the imaging range of the axial 3D MR-S. We concluded that a single unilateral sagittal 3D MR-S was sufficient and axial 3D MR-S was unnecessary for SS staging. T1- and T2-weighted images are essential for investigating the salivary glands in patients with SS. Therefore, we also concluded that bilateral sagittal 3D MR-S of the parotid glands in addition to T1- and T2-weighted imaging is necessary, sufficient, and most efficient for precise MR imaging examination of the salivary glands, including diagnosing SS.

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.

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.

Imaging in Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by dysfunction and lymphocytic infiltration of the salivary and lacrimal glands. Besides the characteristic sicca complaints, pSS patients can present a spectrum of signs and symptoms, which challenges the diagnostic process. Various imaging techniques can be used to assist in the diagnostic work-up and follow-up of pSS patients. Developments in imaging techniques provide new opportunities and perspectives. In this descriptive review, we discuss imaging techniques that are used in pSS with a focus on the salivary glands. The emphasis is on the contribution of these techniques to the diagnosis of pSS, their potential in assessing disease activity and disease progression in pSS, and their contribution to diagnosing and staging of pSS-associated lymphomas. Imaging findings of the salivary glands will be linked to histopathological changes in the salivary glands of pSS patients.

Comparison of Clinical Characteristics and Magnetic Resonance Imaging of Salivary Glands With Magnetic Resonance Sialography in Sjögren's Syndrome

OBJECTIVES/HYPOTHESIS

To compare the results of magnetic resonance imaging with magnetic resonance sialography (MRSIAL) and the clinical and laboratory characteristics in a well-characterized cohort of patients with primary or secondary Sjögren's syndrome (SS) meeting the American-European Consensus Group criteria.

STUDY DESIGN

Retrospective, observational, monocentric study.

METHODS

Thirty-six patients (81% female, mean age = 48 ± 35 years) with primary or secondary SS who underwent MRSIAL were included in the study.

RESULTS

MRSIAL revealed characteristic radiological signs in the parotid, sublingual, and submandibular salivary glands in 35/36 patients (97%). Patients presenting with anti-Sjögren's syndrome-related antigen A (SSA) autoantibodies showed more often fatty infiltration, a "pepper-and-salt" appearance, ductal stenosis, and/or ductal dilation of the parotid gland (88%, 88%, and 72% respectively) than patients negative for anti-SSA (12%, 4%, and 28% respectively). MRSIAL demonstrated signs characteristic of SS in all 11 patients with negative minor salivary gland biopsy. For 15 patients undergoing ultrasound examination only, 11 (73%) had SS findings, but all 15 had SS findings on MRSIAL. Two cases of parotid lymphoma were detected by MRSIAL (6%).

CONCLUSIONS

MRSIAL is a reliable technique to detect glandular anomalies in patients with SS, and seems to provide a valuable aid in the diagnosis of SS.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E83-E89, 2021.

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.

Diagnostic value of major salivary gland ultrasonography in primary Sjögren's syndrome: the role of grey-scale and colour/power Doppler sonography

Primary Sjögren's syndrome (pSS) is an autoimmune connective tissue disease characterized primarily by chronic inflammatory involvement of the exocrine glands, particularly the salivary glands. The use of ultrasound in the study of salivary glands (SGUS) has expanded considerably in recent years. The ultrasound can document structural alterations that can be visualized as hyperechogenic and hypoechogenic areas, or as areas with non-homogeneous echogenicity. To date, several systems of SGUS scoring systems of abnormalities during pSS are available. From the studies published in recent decades, it has been possible to document the high sensitivity and specificity of the pathological findings that can be documented by SGUS. SGUS can also provide added value in identifying patients at risk for developing disease complications such as lymphoma. The Doppler technique can also supply information about glandular tissue vascularization, which is very useful for diagnostic and differential purposes. In this review we will present the state of the art of SGUS, with a prevailing focus on diagnostic use and possible future developments.

Whole-Volume ADC Histogram Analysis in Parotid Glands to Identify Patients with Sjögren's Syndrome

At present, no gold standard for diagnosing Sjögren’s syndrome (SS) is available in clinical practice. The 2002 American–European Consensus Group classification criteria are used to diagnose SS. Clinically, it is challenging to distinguish patients with SS from suspected patients undergoing different therapies. A total of 52 patients with SS and 24 patients suspected of having the disease prospectively underwent 3.0-T magnetic resonance (MR) scanning, including diffusion-weighted imaging (b = 0 and 1000 s/mm²). The whole-volume apparent diffusion coefficient (ADC) histogram analysis generated ADC_mean, skewness, kurtosis, and entropy values from bilateral parotid glands. Continuous variables were compared using an independent two-sample t test, and categorical variable compared using the Fisher’s test between the two groups. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of the indexes. Fisher’s tests demonstrated that some clinical indexes and MR morphology grades differed significantly between patients with SS and patients suspected of having the disease (all P ≤ 0.001). The parotid entropy value of patients with SS was significantly higher than that of patients suspected of having the disease (P < 0.001). Among MR parameters, entropy combined with kurtosis performed the best in differentiating patients with SS from those suspected of having SS (area under the ROC curve = 0.955). A whole-volume ADC histogram analysis might provide a series of parameters that reflect tissue characteristics.

Relationship of MR imaging of submandibular glands to hyposalivation in Sjögren's syndrome

OBJECTIVE

We analysed the correlation between magnetic resonance images of the parotid and submandibular glands and the salivary flow rate in patients with Sjögren's syndrome.

METHODS

We retrospectively reviewed magnetic resonance images (heterogeneous signal-intensity distribution and gland volume on T1- and fat-suppressed T2-weighted images, and multiple high-signal-intensity spots on magnetic resonance sialograms in the parotid and submandibular glands) obtained from 66 patients who were diagnosed with Sjögren's syndrome. We evaluated the relationship between these imaging features and their salivary flow rates in stimulated and unstimulated conditions.

RESULTS

We found that as the disease progressed, both the heterogeneous signal-intensity distribution and the volumes of the parotid and the submandibular glands were significantly related to the stimulated and the unstimulated salivary flow rate. These imaging features were more highly correlated in assessments of the submandibular gland than in those of the parotid gland for both stimulated and unstimulated salivary flow rates.

CONCLUSIONS

Magnetic resonance image features of heterogeneity and smaller volume in the submandibular gland are reliable for predicting hyposalivation related to the progression of Sjögren's syndrome.

Diffusional kurtosis imaging of parotid glands in Sjögren's syndrome: Initial findings

PURPOSE

To explore the role of diffusion kurtosis imaging (DKI) of parotid glands in diagnosing Sjögren's syndrome (SS).

MATERIALS AND METHODS

A total of 40 patients with SS and 40 healthy volunteers underwent 3.0T magnetic resonance imaging (MRI) including DKI, which generated the apparent diffusion coefficient (ADC), corrected diffusion (D), and diffusional kurtosis (K) values. The MR nodular grade was determined on the basis of MR morphological findings.

RESULTS

The parotid ADC, D, and K values in patients with SS were significantly higher than those of healthy volunteers (P = 0.011, < 0.001, 0.022, respectively). The parotid ADC and D values in patients with SS of MR nodular grade 0 were significantly higher than those of healthy volunteers (all P < 0.001). The parotid D value showed an accuracy of 75.0% and 87.9% in diagnosing patients with SS and MR nodular grade 0, respectively. The parotid ADC and D values correlated negatively, while the K values correlated positively with the MR nodular grade significantly in patients with SS (r = -0.741, -0.605, 0.424, all P < 0.001). All parotid DKI parameters differed significantly among patients with SS at different MR nodular grades (all P < 0.001).

CONCLUSION

Parotid DKI parameters hold great potential in diagnosing SS, especially in early-stage SS without MR morphological changes.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1409-1417.

Use of T1ρMR imaging in Sjögren's syndrome with normal appearing parotid glands: Initial findings

PURPOSE

To explore the feasibility of parotid spin-lattice relaxation time in the rotating frame (T1ρ) MR imaging in the diagnosis of Sjögren's syndrome (SS) without morphological changes of the parotid glands.

MATERIALS AND METHODS

The study enrolled 32 consecutive SS patients without morphological changes of parotid glands and 32 age- and gender-matched healthy volunteers who underwent parotid 3.0 Tesla MR imaging, including T1ρ sequences. Follow-up imaging was performed at 3 months. T1 signal intensities and T1ρ values of bilateral parotid glands were compared using paired samples t-test. Parotid T1 signal intensities and T1ρ values were compared using two independent samples t-test. Diagnostic performance of the parotid T1ρ values was evaluated by receiver operating characteristic analysis. The intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of parotid T1ρ measurements.

RESULTS

There were no significant differences of T1 signal intensities and T1ρ values between bilateral parotid glands in SS patients and healthy volunteers (P = 0.170, 0.886 and 0.942, 0.229). The parotid T1ρ values of SS patients (96.47 ± 15.38 ms) were significantly higher than those of healthy volunteers (84.25 ± 6.11 ms) (P < 0.001), while there were no significant differences of T1 signal intensities between SS patients and healthy volunteers (P = 0.655). With a cutoff value of 88.02 ms, the sensitivity and specificity of the parotid T1ρ value was 75.0% and 100.0% in the diagnosis of SS. The reproducibility of parotid T1ρ measurement was excellent (ICC: 0.934-0.995).

CONCLUSION

Parotid T1ρ MR imaging held a potential role in diagnosing SS without morphological changes of parotid glands.

LEVEL OF EVIDENCE

2 J. Magn. Reson. Imaging 2017;45:1005-1012.

Diagnostic performance of MR imaging of three major salivary glands for Sjögren's syndrome

OBJECTIVE

We analyzed the diagnostic performance of the MR imaging findings of the parotid, submandibular, and sublingual glands to discriminate between patients with and without Sjögren's syndrome.

METHODS

We retrospectively analyzed the correlation between the MR imaging and histopathological findings obtained from 69 patients with clinically suspected Sjögren's syndrome. We evaluated the heterogeneous signal intensity distribution on T1- and T2-weighted images, the multiple high-signal-intensity spots on MR sialograms, and the volume of the parotid, submandibular, and sublingual salivary glands.

RESULTS

The multiple high-signal-intensity spots in the parotid gland showed the highest sensitivity and diagnostic accuracy (82% and 83%, respectively). In addition, the multiple high-signal-intensity spots and the heterogeneous signal intensity distribution in the submandibular gland showed high specificity (100% and 88%, respectively). The volume of the submandibular gland, but not that of the parotid or sublingual gland, was smaller in patients with Sjögren's syndrome.

CONCLUSIONS

The presence of multiple high-signal-intensity spots on an MR sialogram in the parotid gland should be considered the best diagnostic indicator for Sjögren's syndrome. The presence of spots, heterogeneity, and the change to smaller volumes in the submandibular gland were also helpful because of their high specificity, particularly in advanced cases.

Distribution pattern of Sjögren's syndrome: a sialographical study

BACKGROUND/OBJECTIVES

The present controlled sialographical study was conducted to learn more from the horizontal and vertical symmetry of the ductal lesions of the major salivary glands in primary (pSS) and secondary (sSS) forms of the disease.

MATERIALS AND METHODS

A total of 98 patients (38 pSS patients, 38 sSS patients, 22 control subjects) were included in the study. Contrast radiography of both parotid and submandibular glands was performed within the same session. A 6-point scoring system allowed summary indexes for each of the glands to be calculated.

RESULTS

Pansialography was accomplished within 30 min each. The sparsity of the branching pattern of the ducts was the most frequent pathological finding. In pSS, horizontal symmetry was more pronounced in the parotid glands, whereas in sSS it was more pronounced in the submandibular glands. The most discriminating features were the width of the peripheral ducts in the parotid and the number of acinar dilatations in the submandibular glands. The most advanced lesions were found in the left parotid gland.

CONCLUSION

The peripheral ducts are more affected by SS than the main excretory duct. There is a tendency for asymmetric involvement of the parotid glands in pSS and of the submandibular glands in sSS. Parotid glands are globally more involved than submandibular glands. Differential diagnosis between pSS and sSS cannot be accomplished by means of pansialography alone. Left parotid sialography is recommended for routine use.

Bilateral multicystic parotid masses in primary Sjögren syndrome

We report the case of a 48-year-old woman who presented with bilateral parotid gland enlargement as the initial manifestation of primary Sjögren syndrome. Magnetic resonance imaging demonstrated multiple areas of low-intensity signal mixed with foci of high-intensity signal, a finding suggestive of Sjögren syndrome. Autoimmune blood tests for Sjögren syndrome were positive, and a sublabial biopsy confirmed the diagnosis. Investigations for other conditions, including human immunodeficiency virus infection, were negative. After 5 years of follow-up, the parotid swellings remained essentially unchanged. We discuss the etiology of multicystic parotid gland pathology, its involvement in Sjögren syndrome, and the risk of lymphoma.

Diagnostic accuracy of parotid CT for identifying Sjögren's syndrome

PURPOSE

To evaluate the diagnostic accuracy of computed tomography (CT) of the parotid gland for Sjögren's syndrome in comparison with conventional X-ray sialography.

METHODS

CT scans and X-ray sialography were performed in 34 patients with confirmed Sjögren's syndrome and 22 symptomatic controls without the disease. CT data from 57 asymptomatic controls were included for quantitative analysis. The CT findings of heterogeneity, abnormal diffuse fat tissue deposition, diffuse punctate calcification, swelling or atrophy, nodularity or cystic changes of the parotid gland were analyzed by two independent blinded readers. The correlation between CT and X-ray sialography findings was evaluated. Diagnostic performance and receiver operating characteristics curves were calculated.

RESULTS

On CT, heterogeneity of the parotid gland was seen in 30/31 (reader 1/reader 2) Sjögren's syndrome patients by the two readers (sensitivity 88.2%/91.2%; specificity 100%/90.9%). Abnormal diffuse fat tissue deposition was seen in 28/28 SS patients by the readers (sensitivity 82.3%/82.3%; specificity 100%/90.9%). Diffuse punctate calcification was seen in 10/12 Sjögren's syndrome patients (sensitivity 29.4%/35.2%; specificity 100%/100%). Stagings of CT findings correlate positively with sialography. The areas under the receiver operating characteristics curves were 0.887 (P=0.000) and 0.908 (P=0.000) for the maximum and standard deviation (SD) of the CT value.

CONCLUSIONS

Parotid CT is accurate and reliable in the diagnosis of Sjögren's syndrome. Heterogeneity, abnormal diffuse fat tissue deposition, and diffuse punctate calcification are specific for Sjögren's syndrome. CT attenuation analysis is helpful in diagnosis.

Relationship of the unstimulated whole saliva flow rate and salivary gland size estimated by magnetic resonance image in healthy young humans

OBJECTIVE

The aim of this study was to examine the relationships between gland sizes and the flow rate and composition of the unstimulated whole saliva in humans.

DESIGN

In 28 healthy young adults, the sizes of the three major salivary glands were estimated by use of a magnetic resonance (MR) imaging technique. Unstimulated whole saliva was collected for 5 min by the spitting method, and the flow rate and the concentrations of total protein, Na(+) and K(+) and pH were measured.

RESULTS

The estimated sizes of the parotid and submandibular glands showed a significant positive correlation with the flow rate and the secretion rate of total protein in the unstimulated whole saliva, but that of the sublingual glands did not. Concerning the concentrations of Na(+) and K(+) and pH, there were no correlations with the salivary gland sizes.

CONCLUSIONS

The results suggest that the larger the sizes of the parotid and submandibular glands, the faster the fluid flow and protein secretion rates in unstimulated whole saliva.

Fast and high-resolution MR sialography using a small surface coil

PURPOSE

To establish a fast and high-resolution MR sialographic technique that provides fast and high-resolution imaging.

MATERIALS AND METHODS

MR sialography was performed on a 1.5-T MR imager using a small (47-mm) surface coil. We determined appropriate sequence parameters, and then applied the technique to the salivary glands of 143 patients with xerostomia (including those with Sjögren's syndrome or hyperlipidemia) or salivary gland inflammation. We compared the high-resolution MR sialography with conventional x-ray sialography in the patients with xerostomia to evaluate the effectiveness of the MR sialography technique.

RESULTS

We found that a single-shot, single-slice MR sialography (TR/TR/number of signal acquisitions [NSA] = 8000 msec/1000 msec/6) using a small surface coil provides excellent duct images that are clinically feasible with fast (imaging time of 56 seconds) and high-resolution images. An alternative three-dimensional MR sialography technique provided better details of the branches at the expense of imaging time. The MR sialography technique using a small surface coil depicted effectively the ductal changes in the salivary glands in patients with or without Sjögren's syndrome, reflecting the severity of the diseases.

CONCLUSION

We conclude that MR sialography can be performed using a fast and high-resolution sequence.

Lymphocytic infiltration and enlargement of the lacrimal glands: a new subtype of primary Sjögren's syndrome?

PURPOSE

To review the clinical, radiologic, serologic, histopathologic, immunohistochemical, and molecular genetic features of patients having Sjögren's syndrome (SS) with lacrimal gland enlargement.

DESIGN

Retrospective case series review.

PARTICIPANTS

Fourteen patients histopathologically diagnosed with SS with lacrimal enlargement. Twenty-three age- and gender-matched controls were used for comparison on radiologic analysis.

METHODS

Clinical and serologic data were determined directly or by chart review. Computed tomography images from patients were compared with those from the control group. Histopathologic sections were reviewed and graded using the Chisholm-Mason scale, and quantitative immunohistochemical analysis was applied.

MAIN OUTCOME MEASURES

Clinically, patients were assessed for age, gender, onset, symptoms and signs, systemic features, treatment, and outcome. Existing histologic specimens were reviewed according to the Chisholm-Mason scale, and then the percentages of plasma cells containing immunoglobulin (Ig) A, IgG, and IgM were determined. Imaging was assessed for lacrimal gland thickness, prolapse, density, and margin contour; extraocular muscle size; orbital tissue displacement; and proptosis.

RESULTS

Clinical and histopathological data fulfilled the revised American-European criteria for primary SS in 79% of patients. Compared with other large series of primary SS patients, similarities were found with age, xerophthalmia, parotidomegaly, and articular involvement. Differences included a lower incidence of autoantibodies, xerostomia, and extraglandular features and a higher male-to-female ratio. In almost all patients (93%), the percentage of plasma cells positive for IgA was less than 70%, consistent with SS. Compared with controls, the lacrimal glands were enlarged significantly (P<0.0001) and prolapsed (P<0.001). Involved glands had blurred margins (P<0.007), caused displacement of adjacent tissues (P = 0.03), and were associated with hyperdense fat (P = 0.007). Lymphocytic infiltration of orbital fat was present in all patients for whom fat biopsy results were available. Three patients had monoclonal infiltrates, and 1 patient experienced subsequent extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type, 4 years after presentation.

CONCLUSIONS

The criteria used to diagnose primary SS are controversial, but both diagnostic and quantitative immunohistochemical criteria suggest that these patients, with lacrimal gland enlargement resulting from lymphocytic infiltration, represent a new subtype of primary SS. This is clinically important in view of the increased risk of lymphoma associated with SS, compared with idiopathic nonspecific lacrimal inflammation.

Xerostomia Secondary to Sj??gren???s Syndrome in the Elderly

Xerostomia is a common symptom in the elderly population. Studies have suggested that the underlying cause of approximately 40% of xerostomia in the elderly is Sjögren's syndrome. Although it is highly prevalent among middle-aged individuals, elderly patients account for up to 20% of Sjögren's syndrome cases. Sjögren's syndrome is a multisystem exocrinopathy characterised by dry mouth and dry eyes with wide-ranging extraglandular involvement. The exocrine manifestations of Sjögren's syndrome affect the mouth, eyes, nose, ears, skin, vagina and the entire respiratory and gastrointestinal systems. The nonexocrine involvement may include the joints, thyroid gland, liver, kidneys and the musculoskeletal, vascular and central nervous systems. Currently, the mechanism(s) of development and progression of Sjögren's syndrome is/are not clear. Inflammation and lymphocytic infiltration of the exocrine glands is a classical feature of Sjögren's syndrome. During the progression of the disease, the acinar cells of the exocrine glands are replaced by fibrosis, rendering the glands nonfunctional. Sjögren's syndrome remains one of the most underdiagnosed conditions, particularly in the elderly population, because the cardinal sicca symptoms, which are the hallmark of the disease, are frequently attributed to aging and/or medications, which consequently delays the diagnosis. This delay in diagnosis imposes significant physical, psychological and economic burdens on elderly patients. The diagnosis of Sjögren's syndrome requires evaluation of both the exocrine and nonexocrine components of the disease. Management of Sjögren's syndrome requires collaboration by the primary-care physician, rheumatologist, ophthalmologist and dentist. This article reviews current understanding of the clinical manifestations, diagnosis and treatment of Sjögren's syndrome with special emphasis on the oral component of the disease.

Current issues in Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune and rheumatic disorder with prominent sicca complaints from the mucous membranes because of lack of proper exocrine secretions. There is no straightforward and simple diagnostic test for Sjögren's syndrome, although several classification criteria have been designed including several oral diagnostic tests. A new set of classification criteria in a joint effort by research groups in Europe and USA has recently been presented. A large number of autoantibodies have been reported in Sjögren's syndrome where, in some cases, the antibodies are correlated with the extent and severity of disease. The finding of serum autoantibodies directed against the muscarinic M3 receptor is an important advance in understanding the pathogenesis of not only the impaired glandular function but also associated features of autonomic dysfunction in some patients. The treatment of primary Sjögren's syndrome is still mainly symptomatic.