Role of periodically rotated overlapping parallel lines with enhanced reconstruction diffusion-weighted imaging in...

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.

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.

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/mm(2), 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).

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.