Which error causes partial volume averaging in CT imaging?

Partial volume averaging occurs when a voxel in a CT image contains more than one type of tissue, leading to a blend of their respective densities. This blending happens because the voxel's size does not correspond to the size of the anatomic structures within it. When multiple tissues, each with different attenuation properties, are averaged together during image reconstruction, the resulting pixel value in the image may not accurately represent any single tissue type.

The correct option specifically highlights this phenomenon by indicating that averaging multiple tissue types into one voxel results in partial volume effects. This effect can obscure fine details and may lead to misinterpretation of the imaging results since differing tissue types can have significantly different appearances.

Other options focus on unrelated aspects of CT imaging. For example, using a large display field-of-view (DFOV) can affect the perceived resolution of the image displayed but does not inherently cause partial volume averaging. Detector miscalibration may lead to inaccuracies in the image but does not directly relate to the average of multiple tissue types. Additionally, a wide x-ray beam can influence the dose distribution and the resultant image quality, but it does not specifically correlate with the averaging of different tissue types within a single voxel.

In summary, averaging multiple tissue types into one voxel directly leads to partial