Fig. 7.2 MRI. The Þgure shows very irregular parotid ducts bilaterally, a typical Þnding in a patient with severe symptoms of SjšgrenÕ syndrome. a Axial T1 weighted MR image clearly showing the irregular parotid glands.

Fig. 7.3 MR sialogram. Sagittal MR image with contrast, showing a slightly irregular parotid duct. We also see a cyst in contact with the duct, a typical Þnding in SjšgrenÕs syndrome. We do, however, not see a ÒChristmasÓ tree, but still it shows the same pattern as can be observed in conventional sialograms

Some of the submandibular glands may be seen as well and appear to be just as irregular. b Axial image with fat saturation technique, showing the same patient as in (a)

diagnosis of tumors but so far not in SjšgrenÕs syndrome. Although a time-consuming and expensive method to perform, requiring experienced interpretation of the images, at present MRI represents state-of-the-art in imaging of the salivary glands and possibly the primary imaging modality for SjšgrenÕs syndrome.

7.5Nuclear Medicine

7.5.1 Scintigraphy

Scintigraphy is a method used to evaluate the function of the salivary glands. Technetium 99m

Tc-sodium pertechnetate (99mTc-PT) is used, and the velocity and density of this marker is observed and evaluated in the salivary glands. The radioactively marked ßuid is injected intravenously, and the examination is performed when/as the marker is expected to be in or pass the glands. Several registrations are necessary to achieve a dynamic examination. The examination is a registration of the amount of radioactively marked substance. In regard to SjšgrenÕs syndrome, scintigraphy is commonly used to determine whether the patient responds to stimulation or not. A dynamic scintigraphy will give information about the function of the salivary glands [25].