Diffusion-weighted imaging combined with dynamic contrast-enhanced MRI in parotid gland tumors / 中国医学影像技术

ABSTRACT

Objective To explore the value of DWI combined with dynamic contrast-enhanced MR imaging (DCE MRI) in differential diagnosis of benign and malignant parotid gland tumors.Methods DWI and DCE-MRI was performed in 90 patients with parotid gland tumors (94 lesions),included 75 benign tumors and 19 malignant tumors.The ADCs were measured,and the type of time-intensity curve (TIC) was assessed.ROC curve was used to analyze the diagnostic efficacy of ADC values,TIC types and combination of the two methods in diagnosing benign and malignant tumors.Results The ADC values of malignant tumors ([1.02 ± 0.25] × 10a mm2/s) were significantly smaller than that of benign tumors ([1.38±0.44] × 10-3 mm2/s;t=5.170,P＜0.001).The sensitivity was 0.62 and specificity was 0.92,when type A (persistent),B (washout),and D (flat) tumors regarded as benign and type C (plateau) tumors regarded as malignant.Sensitivity and specificity were significantly improved in diagnosis of malignant tumors when combined type C and ADC＜1.36× 10-3mm2/s,which were 0.92 and 0.95,respectively.Conclusion Due to an overlap within benign and malignant parotid tumors,the diagnosis should not be addressed on the basis of ADC values alone.The TIC manifestations type A,B or D on DCE-MRI indicates benign parotid tumors,and type C indicates malignant diseases.When the TIC shows type C,combining ADC value can elevate the differential diagnostic efficacy of benign and malignant parotid tumors.