Influence of Radiation Dose on Image Quality

Abstract

When the speed of a recording medium is doubled the background quantum mottle is increased by a factor square root 2. However, the signal/noise ratio is changed not in proportion to the square root of the exposure, but in a linear fashion, i.e. by a factor 2. The change in the depiction of objects with a very high attenuation difference in relation to its surroundings appears not to be linear, but proportional to the square root of the exposure. Such objects (metal wire meshes, lead bar grids) should thus be avoided in routine evaluation of image quality since they give incomplete information as to image impairment when high-speed recording media are used.

Relevance of Radiographic Resolution Capacity

“…In previous reports (SELIN et colI. 1975, SELIN & REICHMANN 1977, REICHMANN et coil. 1978, REICHMANN & ASTRAND 1979, several sources of error inherent in this simplified evaluation procedure have been pointed out.…”

“…1975, SELIN & REICHMANN 1977, REICHMANN et coil. 1978, REICHMANN & ASTRAND 1979, several sources of error inherent in this simplified evaluation procedure have been pointed out. Since the misuse of resolution phantoms of the type described is very widespread, this matter is now treated more comprehensively than before.…”