To standardize quantitative parotid gland scintigraphy for diagnosing Sjögren's syndrome (SS).
Forty-five patients with SS and 23 controls were studied. Dynamic images were obtained up to 50 min after the injection of 185 MBq 99mTc-pertechnetate and salivary excretion was stimulated with lemon juice orally at 40 min after the injection. Peak count and uptake speed in the uptake phase, and excretion speed and excretion fraction in the excretion phase were calculated.
The levels of peak count, uptake speed, and excretion speed in the patients with SS were significantly lower than the levels in the controls, whereas there was no significant difference of excretion fraction level between the patients with SS and the controls. The calculations of peak count and excretion speed levels, which were closely related with the focus scores of minor salivary glands and the amount of stimulated whole saliva, showed higher reproducibility, sensitivity, and specificity than those of uptake speed and excretion fraction levels.
The calculations of peak count and excretion speed were eligible to standardize quantitative parotid gland scintigraphy for diagnosing SS.