What artifact is most commonly produced by patient movement during exposure?

What artifact is most commonly produced by patient movement during exposure?

• A. Ring artifact
• B. Blooming
• C. Motion blur
• D. Scatter

Answer: (C)

Motion during exposure causes motion blur because the image is formed by accumulating photons over the exposure time. If the patient moves at any point, the same anatomy occupies different positions, so the recorded signal becomes a superposition of slightly shifted images. That smears fine details and reduces sharpness along the direction of the movement, which is exactly what we mean by motion blur. To minimize it, shorten the exposure time, use immobilization, and give clear hold-still instructions. Ringing artifacts arise from detector calibration or electronics issues and appear as circular rings, not from patient motion. Blooming is a bright-structure effect where very dense objects spill into adjacent areas, common in CT reconstructions, and isn’t caused by movement. Scatter is the hazy fog from photons deflected by matter and is related to beam energy and patient size, not motion.

Motion during exposure causes motion blur because the image is formed by accumulating photons over the exposure time. If the patient moves at any point, the same anatomy occupies different positions, so the recorded signal becomes a superposition of slightly shifted images. That smears fine details and reduces sharpness along the direction of the movement, which is exactly what we mean by motion blur. To minimize it, shorten the exposure time, use immobilization, and give clear hold-still instructions.

Ringing artifacts arise from detector calibration or electronics issues and appear as circular rings, not from patient motion. Blooming is a bright-structure effect where very dense objects spill into adjacent areas, common in CT reconstructions, and isn’t caused by movement. Scatter is the hazy fog from photons deflected by matter and is related to beam energy and patient size, not motion.