Sonography as a replacement for sialography for the diagnosis of salivary glands affected by Sjögren's syndrome.

LETTERS Sonography as a replacement for sialography for the diagnosis of salivary glands affected by Sjögren's syndrome Recently, it has been suggested that sono-graphic evaluation of the salivary glands is useful in the diagnosis of Sjögren's syndrome. Kawamura et al and, more recently, Ariji et al, showed that descriptive and quantitative assessment of the salivary glands by sonogra-phy efficiently differentiated between diseased and normal glands in patients with Sjö-gren's syndrome. 1 2 They showed that the proposed sonographic gradings correlated well with the sialographic gradings. These findings suggest that sonography might be an alternative diagnostic tool for Sjögren's syndrome. Here, we attempted to determine whether sonography can take the place of sialography as an alternative technique for the assessment of salivary gland involvement in Sjögren's syndrome. Sialography and sonography were performed on 294 patients who presented with sicca syndrome (171 positive and 123 negative for Sjögren's syndrome). We diagnosed patients with Sjögren's syndrome on the basis of the criteria of the European Community Study Group. 3 Sonographic features characteristic of Sjögren's syndrome are heterogeneous echogenicity with hypo-and hyperechoic signals throughout the affected gland (fig 1). 2 Table 1 shows the performance of each of the diagnostic criteria. Sialography performed best among the five diagnostic criteria—that is, sialography, functional tests (Saxon and Schirmer), and serological tests (SS-A and SS-B). Interestingly, when used instead of sialography, sonography provided a good performance , comparable with that of sialogra-phy (McNemar test, p=0.067). 4 In contrast, the other diagnostic criteria did not perform as well as the two imaging criteria. Logistic regression analysis was performed to identify diagnostic criteria that might be used as predictive indicators for differentiating between patients with and without Sjögren's syndrome. 5 Univariate logistic regression analysis showed that the six diagnostic criteria assessed (sialography, sonography, Saxon's test, Schirmer test, SS-A, and SS-B) did correlate with a positive diagnosis of Sjögren's syndrome, indicating that these six criteria, if used alone, could effectively predict the presence of Sjögren's syndrome (table 1). On multivariate analysis, however, only sialography and sonography showed significant correlations with a positive diagnosis of Sjögren's syndrome (table 1); when sialogra-phy was used together with the functional and serological criteria, only sialography showed a significant correlation. If sonogra-phy was used instead of sialography, only sonography displayed a significant correlation with a positive diagnosis of Sjögren's syndrome (table 1). Collectively, these findings suggest that the sonography performs as well as sialography in …