This report aimed to evaluate the effectiveness of high-resolution ultrasound compared with conventional sialography in the diagnosis of Sjögren's syndrome (SS) and to establish whether less invasive ultrasound could replace sialography as a diagnostic investigation.
Clinical records and examination results of 105 consecutive subjects investigated contemporaneously by ultrasound and sialography of the parotid glands for SS were reviewed retrospectively. Results were compared against the final diagnosis established on the basis of revised international classification criteria for SS. 45 subjects were excluded from the study due to incomplete records. Of 60 remaining subjects under investigation for SS, 45 were confirmed (36 primary SS, 9 secondary SS), the remaining 15 subjects being proven not to have the condition.
Ultrasound showed a decreased and heterogeneous honeycomb pattern of parotid gland reflectivity in patients with SS, while sialography demonstrated a punctate pattern of sialectasis. Sensitivity, specificity and accuracy for ultrasound were 84.44%, 73% and 81.6%, respectively, and for conventional sialography were 77.77%, 86.66% and 80%, respectively. The diagnostic difference between the two investigations approached significance (P = 0.074). By combining both imaging modalities, sensitivity increased to 91% with 60% specificity and 83.3% accuracy. There was no significant difference between investigations when diagnosing primary vs secondary SS.
High-resolution ultrasound is a useful, non-invasive and more sensitive alternative to sialography as a diagnostic test in patients with suspected SS. Accuracy may be increased by supplementing ultrasound with sialography.