DIAGNOSTIC VALUE OF ULTRASONOGRAPHY ON SALIVARY GLANDS IN PRIMARY SJOGREN'S SYNDROME

초록

Background: Although biopsy of salivary gland, parotid sialography, salivary gland scintigraphy and unstimulated salivary flow examination have been accepted as diagnostic tools for salivary gland involvement in Sjögren's syndrome, they are not favored due to invasiveness, high costs. New modality with less invasiveness and lower cost has been widely searched. Objectives: The purpose of this study is to examine salivary glands in primary Sjögren's syndrome patients with anti-Ro/SS-A antibody and in normal controls without evidence of Sjögren's syndrome by using ultrasonography (US) in order to evaluate the diagnostic value for the assessment of salivary gland involvement in Sjögren's syndrome. Methods: Thirty patients meeting the criteria for Sjögren's syndrome were included in this study and sex and age-matched thirty subjects without any evidence suggestive of Sjögren's syndrome were enrolled as control group. Ultrasonography was performed on both parotid and submandibular glands and routine images were obtained in longitudinal and transverse planes. The US findings of salivary glands in Sjögren's syndrome were defined as parenchymal inhomogeneity (PIH) with blurred glandular border, diffuse multiple hyperechoic bands and hypoechoic areas. PIH of salivary gland was graded into four categories according to diameter of hypoechoic areas. US images were analyzed independently by two rheumatologist blinded to the clinical diagnosis and inter-observer agreement was analyzed by kappa test. Results: PIH of parotid gland was visualized in 25 (83.3%) Sjogren's syndrome patients and 2(6.7%) control subjects while PIH of submandibular gland was observed in 24 (80%) Sjogren's syndrome patients and in 2 (6.7%) control subjects. Thus, sensitivity and specificity of PIH at the parotid and submandibular gland were 83.3%, 93.3% and 80%, 93.3%, respectively. Positive and negative predictive values were 92.6%, 84.8% at the parotid gland and 92