Visualization of inner ear structures by three-dimensional high-resolution magnetic resonance imaging.

High-resolution computed tomography (CT) has long been the method of choice in the visualization of the petrous bone, the internal auditory canal, and the cerebellopontine angle. The introduction of magnetic resonance imaging (MRI), especially of the three-dimensional Fourier transformation constructive interference in steady state (3DFT-CISS), has proved to be superior in the detection of soft-tissue lesions in the inner ear. The aim of this study was to visualize small anatomic structures of the inner ear and cerebellopontine angle. The examinations were performed with a standard head coil on a 1.5-T Magnetom ("Vision"; Siemens, Erlangen, Germany). The three-dimensional reconstruction of the cochlea, semicircular canals, and vestibulum allowed detailed visualization, as well as the imaging of cranial nerves VII and VIII. Our results indicate that 3DFT-CISS MRI is a valuable diagnostic tool in the evaluation of inner ear anatomy and pathology; in most cases, however, it must be supplemented by HR-CT.