Mastoid size determined with lateral radiographs and computerized tomography.

Minimal pneumatization of the temporal bone is characteristic of otitis media. The classic radiographic assessment of mastoid air cell system size is the Runstrom II view, but the Law lateral view is the commonly used clinical view in the United States. Isolated temporal bone specimens are most accurately positioned using a modified Law lateral view (with the film perpendicular to the central X-ray beam). Computerized tomography is the best radiographic means of assessing mastoid pneumatization. The mathematical relationships of mastoid pneumatization size determined by the Runstrom II, Law, and modified Law lateral radiographs, and computerized tomography were determined in 30 adult cadaver specimens. These data may facilitate additional study of otitis media.