Image processing in electron tomography

Electron tomography (ET) has emerged as the leading technique for three-dimensional (3D) structural analysis of unique complex biological specimens. ET makes it possible to directly visualize the molecular architectures of organelles, cells and complex viruses at close-to-molecular resolution. ET has been crucial to reveal some of the major breakthroughs in life sciences in the last few years. ET combines electron microscopy with the power of 3D imaging to derive the 3D structure of complex specimens. A number of computational stages are involved in a typical structural study by ET, which range from the image acquisition with the electron microscope to the 3D reconstruction by means of tomographic reconstruction algorithms. Afterwards, a number of computational steps are necessary to facilitate the interpretation of the 3D data: noise reduction, segmentation and analysis of subvolumes. This chapter reviews the different computational stages involved in ET, from image acquisition to interpretation of the 3D reconstruction.