Objective. - To assess the diagnostic value of parotid gland quantitative assessment using ultrasound (US) as well as magnetic resonance imaging (MRI) in patients with Sjogren's syndrome (SS) and to evaluate the possibility of using such modalities as a predictor of the histopathologic score of salivary gland biopsy in this group of patients.

Methods. - Sonographic and MRI studies were performed on the parotid glands of 47 patients diagnosed to have primary SS, 20 healthy control subjects of matched sex and age, and 20 subjects with sicca symptoms but without any evidence of SS. The patients and the control subjects were scored according to the structural changes seen in both radiologic modalities. In addition, sialography and labial gland biopsy were done for all patients as well as the control subjects and scored according to the degree of affection.

Results. - Parenchymal inhomogenity (PIH) was seen in 93.6% of the patients studied by US, while nodular pattern was seen in 97.8% in the MRI study. The US and MRI results correlated significantly with the histopathologic score of the minor salivary glands (r = 0.82, 0.84, respectively) as well as sialography score (r = 0.69, 0.60, respectively). There was good agreement between US and MRI findings (r = 0.87) in both SS cases and control subjects.

Conclusion. - US and MRI are equally sensitive tools for the diagnosis of salivary involvement in patients with SS. Quantitative assessment of US and MRI images seem to represent an advance in the diagnosis of SS as they offer a good prediction of the pathology score of the salivary gland. MRI seems unnecessary as a routine diagnostic tool and should be considered as the second option in case of normal US.