What type of artifact occurs in the superior portion of the skull due to dense bone averaging with low-attenuating brain tissue?

In computed tomography, various artifacts can affect image quality and interpretation. The phenomenon described in the question pertains to the averaging of attenuation values in areas where there is a significant difference in density, such as between dense bone and softer brain tissue.

Cupping artifact is specifically characterized by the lower attenuation of the periphery of an image compared to the center. This occurs because in areas where there is dense material, like the superior portion of the skull, it can create a situation where the low-attenuating soft tissue of the brain averages out with the higher density bone, resulting in a misrepresentation of the actual imaging data. This artifact manifests as a cupping shape, where the high-density zones create darker areas around them when averaged with the less dense tissues, hence the name.

Understanding this artifact is crucial for radiologic technologists and radiologists because it can lead to misinterpretation of scans and impact clinical decisions. Recognizing how different tissues interact in CT imaging allows for better diagnosis and understanding of the underlying anatomy.