Low dose exposure diagnosis with a transXend detector aiming for iodine-marked cancer detection

The energy resolved computed tomography (CT), which had advantage over conventional CT (twofold higher CT value for iodine contrast agent and being free from beam hardening effect), was shown practical by employing the transXend detector: it measured X-rays as electric current and gave energy distribution of incident X-rays after analysis. This article shows a new application of the transXend detector for estimating the thicknesses of acrylic, iodine, and aluminum in a phantom. For this purpose, the responses of the segment detectors in the transXend detector are changed intentionally with inserting filters. With previously obtained two-dimensional maps for acrylic–iodine and acrylic–aluminum thicknesses, which are shown by the ratios of electric currents measured by the segment detectors, the thickness of materials on the path of the X-rays are obtained by a transmission measurement

Measurement of effective atomic numbers using energy-resolved computed tomography

For ion radiation therapy, the measurement of effective atomic numbers, Z[eff], is necessary to know the material distribution in a human body; the range of ions entering the human body is influenced by the material distribution along their paths. Z[eff], however, cannot be measured at hospitals because monochromatic X-rays with different energies are necessary and are used only at synchrotron facilities. To make Z[eff] measurements at hand, we propose energy-resolved computed tomography (CT) using a “transXend detector”. By assigning two narrow energy ranges in the unfolding process of the data obtained by the transXend detector, Z[eff] for acrylic and aluminum can be estimated by energy-resolved CT. The estimated Z[eff] are compared with those obtained by dual-energy and monochromatic X-ray CT