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Aim: To investigate the role of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging (DWI) in correcting distortion and evaluating head and neck masses. Materials and methods: Both PROPELLER and echo planar diffusion weighted imaging (EP-DWI) with different b values were performed using 3 T MRI in 50 patients with solid masses of the head and neck. Distortion severity of 50 masses with both DWI techniques and different b values was qualitatively scored and compared. The apparent diffusion coefficient (ADC) values of the 45 masses, in which the distortion scores with both DWI techniques were ≥2, were measured and calculated. The mean ADC value of each DWI sequence between benign and malignant masses was compared. Results: The mean distortion scores of PROPELLER DWIs were significantly higher than EP-DWIs (3.87 versus 1.96, and 3.88 versus 2.00, with b values of 1000 and 500 s/mm2, respectively, p < 0.001), indicating distortion of the mass on PROPELLER DWIs was much less than that on EP-DWIs. With either PROPELLER or EP-DWI, the mean ADC value of 24 malignant tumours was significantly lower than that of 21 benign masses (p < 0.001). Conclusion: Severe distortion of head and neck masses can be reduced significantly using PROPELLER DWI. Moreover, PROPELLER DWI plays an important role in differentiating malignancies from benign masses. [Copyright &y& Elsevier]

Aim To evaluate the value of 3 T Periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DUO diffusion-weighted MRI (DW-MRI) in differentiating sinonasal lymphomas from carcinomas. Materials and methods PROPELLER DUO DW-MRI was performed in 23 patients with sinonasal lymphomas and 28 patients with carcinomas histologically confirmed at 3 T MRI. Apparent diffusion coefficients (ADCs) were obtained with two different b-values (b = 0 and 700 s/mm 2 , b = 0 and 1000 s/mm 2 ) and two different regions of interest (ROIs) sampling strategies [whole section (WS), partial section (PS)], respectively. Difference in ADCs between sinonasal lymphomas and carcinomas was evaluated using the independent samples t -test or Mann–Whitney U -test. The utility of ADC thresholds for discriminating between them was evaluated by receiver operating characteristic analysis. Results ADCs of sinonasal lymphomas (WS ADC b0,700 , 0.838 × 10 −3 mm 2 /s) were significantly ( p < 0.001) lower than those of carcinomas (WS ADC b0,700 , 1.396 × 10 −3 mm 2 /s). Using a WS ADC b0,700 value of 1.040 × 10 −3 mm 2 /s as the threshold value effectively differentiated sinonasal lymphomas from carcinomas with 100% sensitivity, 82.1% specificity, and 82.1% positive and 100% negative predictive values and 90.2% accuracy (b = 0, 700 s/mm 2 ). There was no significant difference in diagnostic ability between different b-values settings ( p > 0.05) and different sampling strategies of ROIs ( p > 0.05), respectively. Additionally, there was significant differences in the ADCs between diffuse large B-cell lymphomas and natural killer (NK)/T-cell lymphomas ( p < 0.05). Conclusion PROPELLER DUO DW-MRI can effectively differentiate sinonasal lymphomas from carcinomas. [ABSTRACT FROM AUTHOR]