To Evaluate The Diagnostic Value Of ^99mTc-pertechnetate Salivary Gland Scintigraphy In Patients With Sjogren’s Syndrome

Objective: The aim was to this study to investigate the diagnostic value of uptake ratio of 10min （UR10min） and residual ratio in patients with Sjogren’s syndrome （SS）. And analysis whether there is difference of UR10minand residual ratio between anti-SSA/SSB antibodies positive and negative patients.Methods: 94 patients with Sjogren’s syndrome and 60 patients without Sjogren’s syndrome （control group） were studied by ^99mTc-pertechnetate salivary gland scintigraphy. Oval-shaped region of interest （ROI） were marked over each of parotid gland. Background ROI were marked in temporal. Then calculated UR10min and residual ratio. According to the degree of clarity in parotid gland and the type of time -activity curve were divided SS patients into 3 groups: group A was a function of normal （15 cases） and mild injury （7 cases）.group B was a function of moderate injury （56 cases）. Group C was a function of severe injury （16 cases） . Utilizing the analysis of variance to analyze the different of UR10min and residual ratio between control group and SS patients（group A, group B and group C）. Using the receiver operating characteristic curve （ROC curve） analyze UR10min and residual ratio of parotid gland, And calculated the area under the ROC curve, Youden index , the best cutoff value,sensitivity and specificity. Finally, using the t test of two independent samples to analyze the different of the UR10min and residual ratio between the positive anti-SSA/SSB antibodied and that of negative patients with Sjogren’s syndrome.Results: 1) Compared with group C,The UR10min of parotid gland in control group, group A and group B were obviously higher than that in group C,the difference were statistically significant （P=0.000）. Compared with group A,The UR10min of parotid gland in control group and group B were slightly less than group A , but the difference were no statistically significant （P=0.50,P=0.12）. The UR10min of parotid gland in control group was slightly higher than group B, but the two groups had no statistically significant difference （P=0.22）.2) the residual ratio of parotid gland in control group was significantly smaller than those of the SS patients in group A ,group B and group C, the differences were statistically significant （P = 0.000）. the residual ratio of parotid gland in group A was significantly less than those of the SS patients in group B and’group C, the difference were statistically significant （P = 0.000）. the residual ratio of parotid gland in group C was slightly less than group B, but the difference between the two groups was no statistical significance （P = 0.06）. 3)The area under the ROC curve of UR10min were 0.62, When UR10min of parotid less than 1.01 was taken to be indicative of diagnosis of SS, the sensitivity,specificity, Youden’s index was 0.36, 0.96 0.32. The area under the ROC curve of residual ratio was 0.97, When ^99mTcO₄^- residual ratio more than 0.8 was taken to be indicative of diagnosis of SS, the sensitivity, specificity, Youden’s index was 0.94,0.98, 0.92. 4) Compare the UR10min and residual ratio of parotid gland in patients with Sjogren’s syndrome, there was no significant difference between the positive anti-SSA/SSB patients and the that of negative （P > 0.05）.Conclusions: ^99mTc-pertechnetate salivary gland dynamic imaging can objectively evaluate the function of salivary gland, and it is significant for the diagnosis of SS. UR10min is sensitive to the diagnosis of advanced SS. residual ratio can early evaluated dysfunctions of salivary glands and has important significance in the early diagnosis of SS. So proposes that when parotid residual ratio is more than 0.8, it can be the diagnostic criteria of SS.