The effects of the film/screen combination on tomographic image quality.

Several film/screen combinations were studied to evaluate their effect on thin-section tomograms of the inner ear. Hypocycloidal images of a head phantom were subjectively ranked for image quality, and contrast, spatial frequency spectra, and Wiener noise spectra were measured. Resolution appears to be significantly improved when medium-speed screens are used instead of fast, unsharp screens; observers could perceive increased detail through the higher noise of the medium-speed screens. The authors conclude that medium-speed screens yield more diagnostic information than fast, unsharp screens in thin-section tomography of the inner ear.