Application Value Of DIXON Imaging Of Salivary Glands In Sj(?)gren’s Syndrome

Objective: To investigate the application value of m DIXON-Quant imaging of parotid and submandibular glands in Sj(?)gren’s syndrome(SS).Methods:We Collect 31 SS patients(case group,mean age,50.0±13.5 years;Age range,27.0-72.0 years;BMI,22.8±5.5)who underwent conventional MRI and m DIXON-Quant imaging of parotid and submandibular glands,and the conventional MRI images were graded according to the degree of fat deposition.The mean fat fraction(FF)and standard deviation of parotid and submandibular glands were measured on the FF map of m DIXON-Quant imaging.A control group of 31 healthy volunteers were recruited in pairs based on age and BMI.The differences of parameters between the case group and the control group as well as between different grades of the case group were compared.Defining grade 0 and grade 1 patients as early patients,and compared the parameter differences between early patients and healthy volunteers.Results: In the 31 cases of the case group,58 parotid glands and 44 submandibular glands had fat signal grade > 0.The corresponding m DIXON-Quant sequence FF pseudo-color map showed unevenly distributed high color temperature areas in the glands,which were green,yellow and red.There were no obvious abnormalities in the remaining 4 parotid glands and 18 submandibular glands.The standard deviation and mean value of FF in the parotid and submandibular glands of the case group were significantly different from those of the control group(35.7vs.28.3,28.1vs.4.9,11.7vs.4.5,13.7vs.3.5),and there were no significant differences between the standard deviation and mean value of FF in the parotid and submandibular glands of grade 0subgroup and the control group(32.1vs.28.3,4.8vs.4.9,5.3vs.4.5,3.9vs.3.5),there was no significant difference between the mean value of FF in grade 1 and grade 2 subgroups parotid glands and the control group(27.4vs.28.3,33.9vs.28.3).Parotid gland FF standard deviation,submandibular gland mean FF value and standard deviation had high diagnostic power for SS(AUC=0.949、0.846、0.893).The mean FF value of parotid gland in early patients was not significantly different from that of the control group(28.0vs.28.3),the mean FF value of submandibular gland was significantly different from that of the control group(9.1 vs.4.9),and the standard deviation of FF of parotid and submandibular glands was significantly different from that of the control group(8.2vs..4.5,5.9 vs.3.5).The diagnostic efficiency of parotid gland standard deviation was higher in early patients(AUC=0.898).Conclusion: The mean FF value and standard deviation of the salivary glands can be a good assessment of the degree of fat deposition in patients with SS.The parotid gland FF standard deviation,the submandibular gland mean FF value and standard deviation have higher diagnostic efficiency for SS,but the parotid mean FF value is lower.For patients in the early stage of the disease,the mean value of single assessment cannot truly reflect the changes in parotid gland fat deposition.Analysis of mean combined with standard deviation can improve the diagnostic performance of m DIXON-Quant for SS.The mean FF value and standard deviation of the submandibular glands can be a good assessment of the fat deposition of the glands in early patients.