INCOHERENT-SCATTER COMPUTED-TOMOGRAPHY WITH MONOCHROMATIC SYNCHROTRONX-RAY - FEASIBILITY OF MULTI-CT IMAGING-SYSTEM FOR SIMULTANEOUS MEASUREMENT OF FLUORESCENT AND INCOHERENT-SCATTER X-RAYS

We describe a new system of incoherent scatter computed tomography (IS CT) using monochromatic synchrotron X rays, and we discuss its potenti al to be used in in vivo imaging for medical use. The system operates on the basis of computed tomography (CT) of the first generation. The reconstruction method for ISCT uses the least squares method with sing ular value decomposition. The research was carried out at the BLNE-5A bending magnet beam line of the Tristan Accumulation Ring in KEK, Japa n. An acrylic cylindrical phantom of 20-mm diameter containing a cross -shaped channel was imaged. The channel was filled with a diluted iodi ne solution with a concentration of 200 mu gI/ml. Spectra obtained wit h the system's high purity germanium (HPGe) detector separated the inc oherent X-ray line from the other notable peaks? i.e., the K-alpha and K-beta 1 X-ray fluorescent lines and the coherent scattering peak. CT images were reconstructed from projections generated by integrating t he counts in the energy window centering around the incoherent scatter ing peak and whose width was approximately 2 keV. The reconstruction r outine employed an X-ray attenuation correction algorithm. The resulti ng image showed more homogeneity than one without the attenuation corr ection.