Imaging characterization of a parotid mass is crucial for determining the best therapeutic option.
Multiparametric MRI is the imaging modality of choice for the investigation of parotid tumors.
Some MRI features are highly suggestive of a specific diagnosis.
Combining morphological features with diffusion-weighted imaging and dynamic-contrast enhanced imaging improves the capabilities of MRI for the diagnosis of parotid tumors.
The purpose of this systematic review was to provide an overview of the contribution of multiparametric magnetic resonance imaging (MRI) in the diagnosis of parotid tumors (PT) and recommendations based on current evidences.
Material and methods
We performed a retrospective systematic search of PubMed, EMBASE, and Cochrane Library databases from inception to January 2020, using the keywords “magnetic resonance imaging” and “salivary gland neoplasms”.
The initial search returned 2345 references and 90 were deemed relevant for this study. A total of 54 studies (60%) reported the use of diffusion-weighted imaging (DWI) and 28 studies (31%) the use of dynamic contrast-enhanced (DCE) imaging. Specific morphologic signs of frequent benign PT and suggestive signs of malignancy on conventional sequences were reported in 37 studies (41%). DWI showed significant differences in apparent diffusion coefficient (ADC) values between benign and malignant PT, and especially between pleomorphic adenomas and malignant PT, with cut-off ADC values between 1.267×10−3mm2/s and 1.60×10−3mm2/s. Perfusion curves obtained with DCE imaging allowed differentiating among pleomorphic adenomas, Warthin's tumors, malignant PT and cystic lesions. The combination of morphological MRI sequences, DCE imaging and DWI helped increase the diagnostic accuracy of MRI.
Multiparametric MRI, including morphological MRI sequences, DWI and DCE imaging, is the imaging modality of choice for the characterization of focal PT and provides features that are highly suggestive of a specific diagnosis.Le texte complet de cet article est disponible en PDF.
Keywords : Parotid neoplasms, Magnetic resonance imaging, Diffusion magnetic resonance imaging, Pleomorphic adenoma, Adenolymphoma
Abbreviations : ADC, ADCr, BCA, CEXPA, DWI, DCE, FNAC, GBCA, MRI, PA, PT, ROI, T1WI, T2WI, TIC, Tmax, Tpeak, WR, WT