Head and neck paragangliomas: diffusion weighted and dynamic contrast enhanced magnetic resonance imaging characteristics

BACKGROUND To determine the feature values of head and neck paragangliomas on diffusion-weighted imaging (DWI) and dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI). METHODS Patients with primary head and neck paraganglioma who underwent both DWI and DCE-MRI before treatment between January 2010 and June 2013 were identified. Two radiologists assessed apparent diffusion coefficient (ADC) values on DWI and kinetic characteristics on DCE-MRI. The time intensity curves (TICs) and dynamic parameters, including peak height (PH), maximum enhancement ratio (ER(max)), time to peak enhancement (T(peak)) and maximum rise slope (Slope(max)), were generated and evaluated. RESULTS Ten patients with head and neck paraganglioma were retrospectively analyzed. On conventional MRI, the tumors demonstrated as well-circumscribed, strongly enhanced lesions. Mean ADC value of the lesions was 1.12 ± 0.15 × 10(-3) mm(2)/s. The TICs demonstrated washout pattern (type-III) in all lesions. The mean PH, ER(max), T(peak) and Slope(max) value was 121.24 ± 63.99, 193.79 ± 67.18, 8.16 ± 3.29 and 25.42 ± 7.91, respectively. CONCLUSIONS Head and neck paragangliomas demonstrate distinctive DWI and DCE-MRI results than for other benign tumors which should be taken into account in further evaluation of MRI on head and neck lesions.