Benign and malignant salivary tumours (SGTs) have overlapping clinical, radiologic, and pathologic features. Characterisation of SGTs and precise depiction of deep tumour spread play a key role for treatment planning, surgery being the first therapeutic option in most cases. Therefore, the radiological characteristics of SGTs can help to solve diagnostic dilemmas in many situations thus contributing to adequate therapeutic approaches.

Ultrasound (US) is often used as the initial imaging method in many institutions. Besides its low specificity for the distinction between malignant and benign tumours, US also has a limited sensitivity for tumour detection, especially for deep lobe parotid gland lesions. Nevertheless, US is employed for fine needle aspiration cytology (FNAC) guidance, which is a low-cost technique with a relatively high sensitivity and specificity in SGTs. However, US-FNAC cannot reliably depict deep, distant and perineural spread. Furthermore, the relationship between a tumour and the intra-parotid facial nerve needs to be assessed pre-operatively to adequately plan surgery. 

Computed Tomography (CT) is mainly used in inflammatory diseases in emergency situations, whereas multiparametric Magnetic Resonance Imaging (MRI) is the preferred technique to assess SGTs as CT has an inferior detection rate for tumours and perineural spread and because CT cannot reliably distinguish between benign and malignant SGTs.

Multiparametric MRI with morphologic, diffusion-weighted imaging (DWI) and dynamic contrast enhanced imaging (DCE-MRI) is highly sensitive and specific, and it is considered the most appropriate technique to detect and characterise SGTs.

Nevertheless, both MRI and US-FNAC can yield false positive and false negative results; therefore, in unclear cases, a combined MRI with US-FNAC approach can be helpful.