What artifact results from using thick axial slices in CT imaging?

The correct answer, partial volume averaging, refers to the phenomenon that occurs when a single CT slice encompasses more than one type of tissue or material. When thick axial slices are used, the resultant image averages the different attenuation properties of the various tissues included in that slice. This averaging can lead to misleading representations, where the image may show a mixed density that does not accurately represent any of the individual tissues. For instance, if muscle and fat are both included in a thick slice, the resulting image may not clearly delineate between these tissues, potentially obscuring critical anatomical details.

This artifact can significantly impact diagnostic accuracy, as subtle differences between tissue types might be masked, leading to potential misinterpretations. With thinner slices, this issue is minimized because the imaging captures more localized information, allowing more precise differentiation between adjacent tissues.

Understanding this concept is vital for CT imaging, particularly in settings where accurate anatomical representation is crucial for diagnosis and treatment planning.