What term refers to the volume of tissue represented by a pixel in the matrix used to display the image?

The term that refers to the volume of tissue represented by a pixel in the matrix used to display the image is "voxel." In the context of medical imaging, particularly in CT, a voxel is a three-dimensional element that represents a specific volume of tissue. Each voxel corresponds to a specific value that indicates the density or material composition of that volume, which is crucial for accurately interpreting the images produced.

In contrast, a pixel is a two-dimensional representation in an image and does not convey information about volume. The slice refers to the specific cross-section of the body being imaged and is not synonymous with voxel. The matrix element, while related, does not specifically define the three-dimensional aspect that a voxel provides. Therefore, the correct term that encapsulates the volume aspect in imaging is indeed voxel.