Purpose: This study investigated the effectiveness of major salivary gland ultrasonography (MSGUS) using a new grading system and shear wave elastography (SWE) in evaluating the major salivary glands of patients with Sjögren syndrome (SjS).
Methods: This prospectively-designed cross-sectional study included 49 SjS patients and 49 healthy controls. Major salivary glands were examined with gray-scale ultrasonography and SWE. A new grading system for salivary glands was developed using MSGUS findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MSGUS and shear wave velocity (SWV) values were investigated. The MSGUS grading system and SWV values were evaluated together by logistic regression analysis. A cutoff value of SWE for salivary glands was determined.
Results: The sensitivity, specificity, PPV, and NPV of MSGUS were 69.4%, 73.5%, 72.3%, and 70.6% for the submandibular gland and 69.4%, 65.3%, 66.7%, and 68.1% for the parotid gland, respectively. The mean SWV values of the parotid and submandibular glands were significantly higher in SjS patients than in controls (P<0.05). The sensitivity, specificity, PPV, and NPV for the submandibular gland (cutoff, 1.95 m/s) and the parotid gland (cutoff, 2.39 m/s) were 69.4%, 52%, 59.1%, and 63% and 82.7%, 83.7%, 83.5%, and 82.8%, respectively. Adding SWE to the parotid gland grading system increased the sensitivity and specificity (sensitivity, 82.7%; specificity, 83.7%).
Conclusion: Evaluating the salivary glands using MSGUS with a new grading system and SWE may contribute to the diagnosis of SjS. The combination of MSGUS and SWE may be a promising tool for diagnosing SjS.
Keywords: Elastography; Parotid gland; Submandibular gland; Ultrasonography.