Value of High-Frequency Ultrasonography in the Qualitative and Semi-Quantitative Assessment of Immunoglobulin G4-Related Submandibular Sialadenitis.

Objective-To assess the value of high-frequency ultrasonography in the evalua-tion of immunoglobulin G4-related submandibular sialadenitis (IgG4-SS).Methods-Thirty-four submandibular glands in 17 patients with IgG4-SS were retrospectively enrolled, as well as 34 submandibular glands in 17 healthy control subjects. Qualitative ultrasonic features including submandibular gland size, bor-der, echogenicity, and vascularity were reviewed. Two different scoring systems (0-16 and 0-48, respectively) were used for semi-quantitative analysis of imag-ing features. Comparison of both qualitative and semi-quantitative ultrasonic analysis were made between patients with IgG4-SS and healthy controls. Spear-man correlation was used to explore relationships between variables.Results-The submandibular glands with IgG4-SS presented with enlarged size, rough border, increased vascularity, and abnormal echogenicity (All P < .05). The most common echogenicity pattern for IgG-SS was diffuse hypoechoic foci pattern (44.1%), followed by superficial hypoechoic pattern (20.6%), tumor-like pattern (14.7%), and diffuse hypoechogenicity pattern (11.8%). Most IgG4-SS glands presented linear hyperechogenicity in parenchyma (91.2%). Based on both scoring system, scores of IgG4-SS were significantly higher than those of the controls (All P < .05). Association analysis of both scoring systems showed positive correlation of scores with vascularity in the gland parenchyma (All P < .05).Conclusion-The ultrasonic features of IgG4-SS comprise enlarged gland, rough border, increased vascularity, and abnormal echogenicity, which correlate with its pathological characteristics. The most common echogenicity pattern for IgG4-SS was diffuse hypoechoic foci pattern. Semi-quantitative analysis systems could be useful in the assessment of IgG4-SS. Ultrasound is a potential, valuable, and non-invasive tool for the diagnosis and evaluation of IgG4-SS.