[Comparison of ultrasonography and sialography vs. magnetic resonance in the diagnosis of the primary Sjogren's syndrome].

: To date there is no agreement as to which imaging technique is best for the evaluation of the oral component of primary Sjogren's Syndrome (SS). The purpose of the present study has, therefore, been to determine the reliability of Magnetic Resonance (MR) in the evaluation of salivary alterations in patients with SS. The study involved 23 patients suffering from SS according to the European criteria. All the patients underwent ultrasonography and MR of the major salivary glands, parotid sialography and biopsy of the minor salivary glands. The first control group was made up of 50 healthy subjects who underwent parotid ultrasonography. The second control group comprised 23 subjects who underwent MR of the head and neck for other non parotid pathology. The ultrasonography, MR and sialography images were evaluated by a single observer during a single session and scored from 0 to 4. In the SS patients ultrasonography was abnormal in all 23 cases (100%): 3 patients showed grade 1 alterations (13%); 5 grade 2 (21.7%); 9 grade 3 (39.1%); 6 grade 4 (26.1%). In the healthy controls, grade 0 was found in 36 subjects (72%) while the remaining 14 subjects revealed grade 1 alterations (28%). Using MR imaging only one of the SS patients showed grade 0 alterations (4.3%), 7 showed grade 1 alterations (30.4%), 9 grade 2 (39.1%), 5 grade 3 (21.7%) and only 1 grade 4 (4.3%). MR imaging sensitivity was 95.8% while specificity was 100%. For ultrasonography, considering grade 1 as non pathological, we found a sensitivity of 88.4% and specificity of 100%. The MR score for SS patients was compared to that obtained with sialography and ultrasonography. There was a good correlation between MR and sialography (r = 0.528, p = 0.010) while the correlation between MR and ultrasonography was not statistically significant. This study confirms that, of the diagnostic procedures available for evaluation of salivary gland involvement in SS, the most useful initial examination is ultrasonography. When there is some doubt or there are subtleties, MR is a valid alternative to classical sialography.