Parotid gland evaluation of menopausal women with xerostomia using the iterative decomposition of water and fat with echo asymmetry and least- squares estimation (IDEAL- IQ) method of MRI: a pilot study

Objectives: This study aimed to analyze the quantitative fat fraction (FF) of the parotid gland in menopausal females with xerostomia using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL -IQ) method. Methods: A total 138 parotid glands of 69 menopausal females were enrolled in our study and participants were divided into normal group and xerostomia group. The xerostomia group was divided into those with or without Sj0gren's syndrome. Participants underwent IDEAL -IQ sequences of MRI and the stimulated salivary flow test (s -SFR). The unpaired t -test was used to compare the FFs between the normal and xerostomia groups and between the subgroups with and without Sj0gren's syndrome. The correlation between FF and s -SFR was analyzed by Pearson's correlation. Results: Excellent intra-and interobserver agreement during the measurement of FFs by IDEAL -IQ method (ICC>0.99, respectively). FF value in the xerostomia group was statis-tically significantly higher than the value in the normal group (p < 0.05). Within the xero-stomia group, the average FF value of females with Sj0gren's syndrome was higher than that of females without Sj0gren's syndrome. However, the difference was not statistically significant (p > 0.05). Within the xerostomia group, FF value correlated negatively with s -SFR (p < 0.05).Conclusions: The FF of the parotid gland was higher in the xerostomia group than in the normal group and FF value and s -SFR showed a negative correlation. Analyses of the FF using IDEAL -IQ in menopausal females can be helpful for the quantitative diagnosis of xerostomia.