MRI Findings of Mucoepidermoid Carcinoma of the Parotid Gland
Objective:To assess the conventional magnetic resonance imaging(MRI)and diffusion weighted imaging(DWI)findings of mucoepidermoid carcinoma(MEC)of the parotid gland.Methods:The preoperative MRI data of 42 cases confirmed by pathology,including location,morphology,border,size,homogeneous degree,signal characteristics,apparent diffusion coefficient(ADC)value,enhancement degree and adjacent structure,were retrospectively analyzed.Results:Among 41 MEC patients,40 cases were unilateral single tumor,1 case was unilateral double tumor,21 lesions were located in the superficial lobe of the parotid gland,and 21 lesions spanned the deep and superficial lobes.The maximum diameter of tumors was(2.5±1.0)cm.28 lesions showed irregular morphology,28 had unclear border and 3 possessed capsule.Tumors often demonstrated as iso-intensity on T1WI and hyper-intensity on T2WI.In 7 lesions,the obvious high signal area on T2 showed a compartmentalized and annular very low signal.The ADC value was about(1.05±0.17)×10-3mm2/s.MEC revealed moderate or obvious enhancement after contrast agent injection.14 lesions invaded surrounding structures and 3 had lymph node metastasis.Conclusions:The characteristic MRI manifestations of parotid MEC provided valuable information,such as the tumor extent and adjacent structure invasion,supportive for the determination of therapeutic strategy.