Infographics / Digital Radiography

Digital Radiography Artefacts & Corrections

Six labelled schematic panels of digital radiography artefacts named in the question set. Dead or defective pixels: isolated dead/hot pixels are interpolated and invisible, whereas a line or cluster defect is visible and degrades image quality. Shading or banding from non-uniform detector gain is reversible by flat-field (gain/offset) calibration. Fixed-pattern noise is identical on every image and is removed by calibration, whereas random quantum mottle scales as one over root N, is worse at low mAs, and cannot be removed without blurring. Histogram or LUT error: selecting the wrong histogram window mis-maps the raw signal, giving wrong brightness and contrast, and is a post-processing error not a detector fault. Detector saturation clips signal above the detector maximum to a flat value so information is lost and the artefact is irreversible. Heat blur: intense heat warps or delaminates the receptor, causing unsharpness that focal-spot or SID changes cannot fix. Teal marks recoverable artefacts; rust marks information that is lost or degraded.