What primarily causes unsharpness in radiographic images due to patient movement?

Unsharpness in radiographic images caused by patient movement can occur due to both voluntary and involuntary motion. Voluntary motion refers to movements that the patient consciously controls, such as shifting position or breathing irregularly due to anxiety. Involuntary motion encompasses movements that the patient cannot control, such as those caused by physiological responses (like peristalsis or involuntary muscle contractions) or due to the patient's medical condition (such as tremors).

When radiographic images are produced, any movement during the exposure can blur the image, leading to unsharpness and a reduction in image quality. Because both types of motion can significantly affect the clarity of the image, understanding their roles is essential for improving patient positioning and techniques in radiography to minimize such effects. Thus, the combination of both voluntary and involuntary movements is primarily responsible for unsharpness in radiographic images.