Non-Linear Techniques in Multi-Spectral X-Ray Imaging

The sensitivity of medical radiographs for the contrast agent iodine can be improved by multispectral imaging techniques. Three different shadow projections of the object to be imaged are taken by using three distinct primary X-ray spectra. The corresponding material-selective projections of iodine, bone and tissue masses are generated by combining appropriately the shadow projections. A nonlinear reconstruction algorithm is presented thereby improving the reconstruction accuracy compared with known linear techniques. The algorithm is tested both in computer simulation and in experiment.