Abstract
Electron tomography has been rapidly utilized in biological fields because of the latest instrumental and software developments. The reconstruction algorithm is based on the medical computerized axial tomography (X-ray CT). The principle is the Radon transform and the inverse transform using the projection slice theorem. However, there are several important differences and problems as compared with the medical CT. The major part has been solved by powerful image processing techniques. The most serious problem at present from the viewpoint of the reconstruction algorithm is that a 3-D structure reconstructed by a conventional filtered back-projection is impaired by anisotropic resolution due to instrumentally limited specimen tilt angles. Here, we propose a new approach to overcome the problem by imposing the constraint of the density-existing region on tomographic reconstruction, based on the actual data of specimen's topography measured with multiple stereo analyses. Our approach may substantially improve the 3-D image restoration methodology.
