Added value of diffusion tensor imaging in characterization of parotid gland tumors: bridging current diagnostic gaps

Abstract Background Accurate preoperative differentiation between different parotid gland tumors (PGTs) represents a unique diagnostic challenge and is crucial for appropriate treatment planning. The aim of this study was to evaluate the added value of diffusion tensor imaging (DTI) in the characterization of PGTs. Results The study included 51 patients with PGTs. All patients were subjected to conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) as well as DTI. The mean apparent diffusion coefficient (ADC) values showed a significant statistical difference between all benign and malignant tumors, non-Warthin benign tumors (NWBTs) and Warthin tumors (WTs), as well as between malignant tumors and NWBTs ( P 1 < 0.001 for all). On the other hand, no significant difference was noted between the mean ADC value of malignant tumors and that of WTs ( P = 0.610). On DTI, the mean fractional anisotropy (FA) values showed a significant statistical difference between benign and malignant tumors, WTs and malignant tumors, as well as between NWBTs and malignant tumors ( P < 0.001 for all). However, no statistically significant difference was noted between the mean FA value of WTs and that of NWBTs ( P = 0.315). The highest accuracy for differentiation between benign and malignant tumors, NWBTs and malignant tumors, as well as NWBTs and WTs was achieved by combined ADC & FA (93.4%, 94.6%, 90%) respectively. However, for differentiation between WTs and malignant tumors, it was achieved by FA alone (90%). Conclusions DTI has emerged as an added functional tool to enhance the diagnostic performance of conventional and DWI in the characterization of PGTs without the need for contrast materials. It also gives the possibility to differentiate WTs from malignant tumors which was difficult on the basis of ADC values alone. Combined FA and ADC values can be used to differentiate between subtypes of PGTs with high diagnostic accuracy.