Update of computed tomography and magnetic resonance in otology.

Since my report of 4 years ago at the 8th Shambaugh-Shea Workshop in Otology, equipment and software techniques have continued to evolve with consequent further refinement of imaging studies. Three-dimensional images have greatly improved and have acquired an important role in maxillofacial reconstructive surgery. In otology their value is limited except in congenital atresia. New developments in imaging technique (3-D Fourier transformation) allow sections as thin as 1 mm in any plane. The facial nerve, endolymphatic sac and vestibular aqueduct are well demonstrated but differentiation of the components of the membranous labyrinth is limited. Applications of postcontrast imaging have become more defined for cerebellopontine angle masses, inner ear pathology, and middle ear and facial nerve lesions. Gradient echo techniques and bipolar flow encoding have enabled the development of magnetic resonance angiography. This new, noninvasive procedure is currently useful for the study of aneurysms, vessel stenosis, vascular tumors, and arteriovenous shunts and malformations.