The study of specimen surface topography in transmission electron images requires, for example, the observation of thickness fringe displacements across crystalline samples or, in high resolution, the careful analysis of background phase contrast patterns. Alternatively, a surface may be replicated by shadowing using, for example, Pt/C and although this technique is capable of yielding extremely high topographical resolution, it is difficult to execute and often the original specimen is degraded during removal of the replica. In the present paper we describe the application of a technique which utilizes transmission microscopy and facilitates the study of fine surface features at high resolution. The technique involves the use of tilted illumination such that the main beam is partially obstructed by an axial objective aperture.
Background phase correction in phase contrast velocity encoded CMR reduces gender differences and improves the accuracy and precision of Qp/Qs