How is image brightness defined in radiography?

Image brightness in radiography is defined as pixel light intensity. This refers to the amount of light emitted from each pixel of the digital image, which directly correlates to how bright or dark an image appears on a display. When imaging equipment captures data, it does so by detecting varying levels of radiation exposure, which are then converted into pixel values representing different light intensities. Higher pixel light intensity equates to brighter areas of the image, while lower intensity results in darker areas.

This concept is vital in radiography as optimal image brightness is crucial for accurate interpretation and diagnosis. If the brightness is too high or too low, important details may be obscured or lost, leading to potential misdiagnosis. Proper adjustment of pixel light intensity helps in obtaining a diagnostic-quality image that is neither too dark nor too bright, ensuring the visibility of key anatomical structures.

On the other hand, device contrast pertains to the difference in intensity between the lightest and darkest parts of an image, while image resolution relates to the sharpness or detail of the image. Exposure time affects the overall exposure to the imaging receptor, but it does not directly define brightness since it primarily influences the amount of radiation received.