Tomographic microscopy using synchrotron radiation provides high-resolution structure details on the scale of microns. The field of view (FOV) of the microscopy system, however, is usually limited by the detector size. For example, a typical CCD camera used for data acquisition is of size 2048 by 2048. In many cases this CCD camera is not large enough to provide complete information required for accurate reconstruction, and the local tomography problem hereby arises. On the other hand, the huge dataset generated by tomographic microscopy asks for a highly efficient solution with no a priori information necessary. A new padding scheme is therefore proposed for the local tomography issue. It first pads the projection data using the boundary value inside the FOV, which is specified by the detector size, followed by a zero-value padding to 1.5 times the FOV length. The boundary-value padding removes the energy deposition and cupping artifact in reconstruction results from local tomography, while the zero-value padding reduces the drift of the intensity values caused by fully boundary padding. The combination of two padding schemes keeps advantages of fully zero-value padding and fully boundary-value padding, while avoiding their disadvantages. Quantitative analysis using synthetic data shows that the proposed method outperforms fully zero-value padding and fully boundary-value padding in terms of accuracy and ease for post processing. Experimental results for real data are also provided to demonstrate the effectiveness of the proposed method.

Date Published: 6 March 2013
PDF: 6 pages
Proc. SPIE 8668, Medical Imaging 2013: Physics of Medical Imaging, 86683B (6 March 2013); doi: 10.1117/12.2001550

Published in SPIE Proceedings Vol. 8668:
Medical Imaging 2013: Physics of Medical Imaging
Robert M. Nishikawa; Bruce R. Whiting; Christoph Hoeschen, Editor(s)