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 (ERmax), 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 x 10(-3) mm(2)/s. The TICs demonstrated washout pattern (type-III) in all lesions. The mean PH, ERmax, 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.