Pixels and Voxels - Video Lesson

Welcome back. This lesson is about pixels and voxels in the CT image. A pixel is a two dimensional picture element that we see on the viewing monitor, but these pixels actually represent three dimensions of image information. And we call that three-dimensional block of information a voxel. The term pixel stands for picture elements and the term voxel stands for volume pixel. So where exactly does this third dimension come from in a voxel? It's actually the slice thickness. All of the information in a single three d voxel is averaged together and displayed as a single pixel on the screen. And so even though the pixel is only two dimensional, it is representing three dimensions of data, and that third dimension is the slice thickness. So why does this actually matter? Well,