Radiographic Quality Control

摘要

Apenetrameter (or penny, see Figure 1) is an image quality indicator (IQI), a standardized test subject of known construction and dimensions. It facilitates the judgment of radiographic quality, which is the sum total of the subject contrast, tube contrast, exposure contrast, energy contrast, film contrast, screen contrast, processing contrast, and viewing contrast. IQIs also give indications of resolving power, sensitometry (D_(min), D_(max), speed, contrast), and edge sharpness. If there is a failure, what is the cause?