What would be considered a film artifact in radiography?

A film artifact in radiography refers to any unwanted feature that appears on a radiographic image, which can detract from the quality of the image and may mislead interpretation. Static marks are a specific type of film artifact caused by static electricity, which can create lines or spots on the radiograph that can obscure important details or mimic actual indications of defects.

Static marks often occur when dry film is exposed to low humidity, leading to a buildup of static electricity that discharges and creates these artifacts during processing. This makes them recognizable and distinct from other types of imperfections that may arise from the radiographic process or equipment.

The other options, while they can impact the quality or clarity of an image, do not classify as film artifacts in the traditional sense. Pattern distortion relates to the way the image is displayed and can stem from improper alignment or positioning during exposure, while gradient errors and color shifts are typically associated with issues in development or calibration of imaging systems. These factors affect image quality as well but do not fall under the category of film artifacts in the same way that static marks do.