[Reassessment of usefulness of salivary scintigraphy in diagnosis of Sjögren's syndrome].

Dynamic salivary scintigraphy using 99mTcO4- was performed in 95 patients (a total of 366 glands) suspected of Sjögren's syndrome (SjS) and the results were compared with SjS diagnostic criteria by the Japanese Welfare Ministry. Time-activity curve of ROI created over each salivary gland was classified into four patterns, that is, N, M1, M2, F pattern, depending upon trapping, accumulation and secretion response to the tartaric acid. In definite SjS patients, most of the patients had different patterns in the four glands, and classical F (flat) pattern in all of the four glands was uncommon (3/38, 8%). F and/or M2 (no response to secretary stimulation) patterns were seen in 68.5% (98/143) of the all glands. Provided that F and/or M2 patterns in 2 or more glands is scintigraphic criteria for diagnosis of SjS, sensitivity, specificity and accuracy were 82.9%, 59.5%, 70.8%, respectively. As for salivary uptake of 99mTcO4-, there is a significant difference between the patients with definite SjS and control subjects (parotis p < 0.05, submandibular gland p < 0.01), but there is no significant difference among the patients with definite SjS, suspected SjS and chronic sialoadenitis. In conclusion, the four patterns classification may have potential in screening patients with SjS.