Speaker
Description
X-ray computed micro-tomography (µ-CT) is one of the most advanced and common non-destructive techniques in the field of medical imaging and material science. It allows recreating virtual models (3D models), without destroying the original objects, by measuring three-dimensional (3D) X-ray attenuation coefficient maps of samples on the (sub) µm scale. The quality of the images obtained using µ-CT is strongly dependent on the performance of the associated X-ray detector i.e. to the acquisition of information of the X-ray beam traversing the patient/sample being precise and accurate. Detectors for µ-CT have to meet the requirements of the specific tomography procedure in which they are going to be used. In general, the key parameters are high spatial resolution, high dynamic range, uniformity of response, high contrast sensitivity, fast acquisition readout and support of high frame rates. At present the detection devices in commercial µ-CT scanners are dominated by charge-coupled devices (CCD), photodiode arrays, CMOS acquisition circuits and more recently by hybrid pixel detectors. Monolithic CMOS imaging sensors, which offer reduced pixel sizes and low electronic noise, are certainly excellent candidates for µ-CT and may be used for the development of novel high-resolution imaging applications. The uses of monolithic CMOS based detectors such as the PERCIVAL detector[1] are being recently explored for synchrotron and FEL applications. PERCIVAL was developed to operate in synchrotron and FEL facilities in the soft X-ray regime from 250 eV to 1 keV. Despite its low quantum efficiency, PERCIVAL could offer all the aforementioned technical requirements needed in µ-CT experiments. In order to adapt the system for a typical tomography application, a scintillator is required, to convert incoming X-ray radiation into visible light which may be detected with high efficiency. Such taper-based scintillator was developed and mounted in front of the sensitive area of the PERCIVAL imager.
In this presentation the setup of the detector system and preliminary results of first µ-CTs of reference objects, which were performed in the Tomolab at Elettra, will be reported.
[1] Percival: A soft x-ray imager for synchrotron rings and free electron lasers, A. Marras et al.,
January 2019, Proceedings of the 13TH international conference on Synchrotron Radiation
Instrumentation – SRI2018, DOI: 10.1063/1.5084691
