PubMed Health⌕ Search

Biomedical subjects

R P Porter

Publications and source records attributed to R P Porter.

7 recordsLinked to original sources

Scattered wave inversion by image projections.

A three-dimensional diffraction tomography algorithm based on image projections is implemented. For each view, the measured scattered field is directly backpropagated onto a single plane in the image space. The backpropagated field evaluated on the plane is defined as the image projection because it closely approximates the straight line projection of the object. The object is then reconstructed by parallel slices using conventional straight ray tomographic techniques. This approach permits practical three-dimensional reconstruction using a limited number of views. The reconstructions made with image projections are of comparable quality to ideal diffraction-limited images. By backpropagating the field prior to filtering, curved or misaligned recording surfaces can be used. The limits on the image projection technique for multiple object systems are explored. A diffuse structure is reconstructed.

Algorithms↗

Diffraction tomography by a method of image projections.

A method of three-dimensional diffraction tomography based on image projections is derived. Inversion methods based on projections generally are inaccurate due to the spreading nature of the scattered wave. By backpropagating the field onto a single plane in the image region, diffraction effects are reduced and a projection of the weakly scattering object is generated. Consequently, conventional X-ray inversion techniques may be used to image the object. The relationship between the backpropagated field and the projection is derived both for high frequency incident waves and low spatial frequency scatterers. The generalized image kernel allows the use of curved or misaligned recording surfaces. Numerical results are included.

Algorithms↗