In-line holography and phase-contrast microtomography with high energy x-rays

Holography with high energy x-rays is now feasible due to the coherence pro perties of third generation synchrotron sources. Simple in-line holographic techniques can be used to generate edge-enhanced images which for many sam ples can be interpreted without direct phase retrieval. The coherence prope rties of such sources and their exploitation for phase-contrast microimagin g are demonstrated. The technique can easily be combined with computed micr otomography (CMT) data collection and reconstruction strategies for three-d imensional imaging. A dramatically improved image contrast, as compared wit h absorption CMT, was obtained when imaging a wet human coronary artery spe cimen. In the tomograms, previously invisible detail could be visualized wi th absorbed doses below the level where radiation damage impedes the imagin g. The results indicate the considerable potential of the in-line holograph ic CMT method in three-dimensional biomedical microscopy.