Application Value Of Intravoxel Incoherent Motion Imaging Of Parotid Glands In Sj(?)gren’s Syndrome

Objectives: To explore the application value of intravoxel incoherent motion imaging of parotid glands in Sj(?)gren’s syndrome(SS).Methods: Conventional MR sequence and IVIM sequence scan of bilateral parotid glands were performed in 35 patients with SS but not yet treated and 35 healthy volunteers.The parameters of apparent diffusion coefficient(ADC),diffusion coefficient(D),pseudo-diffusion coefficient(D*),and perfusion fraction(f)were obtained.The morphological diagnosis of the bilateral parotid glands in patients with SS was performed according to conventional MR sequence.Nonparametric Mann-Whitney U test was used to compare the differences of IVIM parameters between SS patients and healthy volunteers.For the comparison of IVIM parameters among different MR morphological grades,nonparametric test Kruskal-Wallis test was used.The intraclass correlation coefficient(ICC)was used to grade the evaluation consistency of the two observers,and ICC > 0.75 showed that the measurement consistency was good.A receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of each significant parameters,and the Spearman correlation analysis was used to explore the correlation between MR morphological grade of bilateral parotid glands and IVIM related parameters.Results : Among the 70 parotid glands of 35 patients with SS,there were 25 parotid glands of grade 0,15 of grade 1,14 of grade 2,5 of grade 3 and 11 of grade 4 according to MR morphological classification.The D*,f of perfusion-related parameters of SS patients were higher than that of healthy volunteers,D* there was no significant difference between the two groups,and the ADC,D of diffusion-related parameters of SS patients was significantly lower than that of healthy volunteers.The ROC curves showed that the sensitivity,specificity,accuracy,and area under the curve(AUC)of MR morphology,ADC、D、f and D* in diagnosing SS patients were63%、86.7%、0.792,76.7%、80.0%、0.856,86.3%、76.7%、0.879,76.4%、64.4%、0.641,respectively,P<0.05.f has good diagnostic efficacy for abnormal changes of parotid gland in early SS,There were negative correlation between ADC 、 D 、 f and MR morphological grades(r=-0.680,-0.699,-0.454,respectively,P<0.05).Conclusions: IVIM sequence can distinguish SS patients from healthy patients,and can diagnose early SS with no abnormalities found on conventional MRI,which can reflect the pathophysiological characteristics of different stages of parotid glands.It has certain guiding value in the evaluation of injury degree of parotid gland in SS.