A quantitative index derived from 99mTc-pertechnetate scintigraphy to assist in the diagnosis of primary Sjögren's syndrome.

A safe and simple technique is reported by which primary Sjögren's syndrome can be detected with a relatively high specificity and sensitivity. The method of serial scintigraphy has been used with reasonable success; however, the application of the linearity index as described here produced superior results. In 71 patients investigated, a sensitivity of 87% and specificity of 93% were recorded and make this the method of choice for evaluating patients suspected of having primary Sjögren's syndrome.