TEXTURE ANALYSIS OF SONOGRAPHIC FEATURES OF THE PAROTID-GLAND IN SJOGRENS-SYNDROME

OBJECTIVE. The purpose of this study was to develop a method for quant itative analysis of the sonographic features of parotid glands as a no ninvasive tool for the diagnosis of Sjogren's syndrome. SUBJECTS AND M ETHODS. Sonographic texture analyses were performed on the parotid gla nds of 44 patients with Sjogren's syndrome, 83 healthy volunteers, and 17 patients with chronic parotitis, using a fast Fourier transform pr ogram. RESULTS. Texture analysis of sonographic studies of the parotid gland using a Fourier transform showed that the sum of the normalized radial power spectrum in the low-spatial-frequency region (S value) o f the parotid gland was significantly higher (p <.0001) in the patient s with definite Sjogren's syndrome [6.70 +/- 2.13 (x10(5))] than in th e 72 age-matched normal Volunteers [3.25 +/- 1.08 (x10(5))]. However, patients with probable Sjogren's syndrome showed S values [3.92 +/- 1. 88 (x10(5))] similar to those of the controls. On the other hand, SDs of the echo levels in the parotid gland showed significantly greater ( p <.0001) values in patients with definite (4.63 +/- 1.07) and probabl e (4.53 +/- 1.47) Sjogren's syndrome than in the normal controls (3.30 +/- 0.76). Discriminant analysis showed that a combination of these t wo distinctive values increased diagnostic accuracy to 96.9%. Furtherm ore, S values and SDs correlated well with the qualitative grading of sonographic features and with the gradings of sialography. CONCLUSION. The system we describe for texture analysis of sonographic images is useful in the diagnosis of Sjogren's syndrome.