MR imaging of the paranasal sinuses and the inner ear

This paper reports evaluates the utility of diffusion-weighted MR imaging of the paranasal sinuses and of the semicircular canals. Diffusion-weighted images of the semicircular canals and paranasal (maxillary) sinuses were obtained in normal subjects as well as in patients with inflammatory and neoplastic diseases involving the sinuses. Diffusion-weighted images differentiated fluid-filled regions from solid tissue. Increased diffusion changes in the semicircular canals and cochlea were observed within the plane of the canals, demonstrating diffusion and fluid motion. Anisotropy of fluid motion was observed along the border of the maxillary sinus walls: Faster apparent diffusion was observed when the gradient was parallel to the wall of the maxillary sinuses with superoinferior orientation, and slower apparent diffusion was noted when the gradient was perpendicular to the sinus wall