What is the cause of the streaking around the patient's right shoulder in a CT image?

Streaking artifacts in a CT image, particularly around areas with high-density materials, are often attributed to the presence of metal within the exposure field. When metal objects—such as dental work, medical implants, or even clothing with metallic fibers—are present, they can disrupt the normal attenuation of X-rays. This disruption leads to inaccuracies in the image reconstruction process, manifesting as streaks or bands in the final image.

The metal causes scattering and beam hardening effects that create visible artifacts, which can obscure anatomical details and complicate diagnosis. This phenomenon is particularly relevant in areas like the shoulder, where medical devices or other metal items may be present.

Understanding this artifact is crucial for interpreting CT images accurately and for taking corrective measures during imaging, such as using different techniques or adjusting patient positioning to minimize metal-related artifacts.