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Digital flat panel detector for x-ray fluoroscopy and radiography


Professional markets (especially medical, but also industrial NDT) have increasing need for direct digital image detectors, of large area, high speed, high resolution, small thickness and high endurance at competitive prices. No existing detector technology such as X-ray Image Intensifier tubes (XRII), CCDs, etc. are expected to satisfy all these user requirements. The main objective of the project is to develop a X-ray Flat panel Detector (XFD) prototype of large area (at 30 x 40 cm) high resolution (pitch 150 cm) at high image speed ("dynamic" at 30 images/sec), following users (medical equipment OEMs) and end users (radiologists) requirements mainly for digital X-rayfluoroscopy and radiography applications A full characterisation of the detector will be performed and a validation of the resulting video images will be done using existing medical X-ray systems. This kind of detector could also be used for industrial (e.g. casting NDT) and food inspection (e.g. glass bottles). The detector is actually considered as the discriminating element or better the bottleneck of a high quality digital image chain. The development of a compact device capable of gathering information and to provide instantaneously to users a digital image, would be an effective breakthrough in X-ray applications allowing higher quality care in medical applications and reduction of Health Care costs due to lower exploitation expenditures. Major advantages of the proposed detector are: high resolution in large view fields; operational flexibility; film equivalent quality; flat and compact detector; high sensitivity / low doses; real time imaging / instantaneous access to the image; potentially lower equipment costs; lower exploitation costs and environmental issues; easier to operate; new potential applications. The proposed XFD is an active matrix detector where each pixel is made of thin film amorphous silicon photodiodes acting as sensitive elements coupled to switching TFTs. X-rays are converted by a scintillator covering the matrix, transforming them in visible light detected by the photodiodes. The pixelised array is matrix-addressed via lines for the row selection and via columns for signal readout. Specific electronics allows to drive and control the detector; pre-processing electronics allows real time data handling functions of the captured image. For the present project, the technology innovation would be mainly in the development of improved panel detectors of large size, at high resolution and high processing speed with low internal noise European medical system, main partners in this project (SIEMENS and PHILIPS) are world leader in the X-ray systems market. The competitiveness of their actual products, mainly based on XRII, would be threatened by the announced introduction in the market by US companies of XFD based systems to substitute film based or XRII based systems. New actors coming from the microelectronics domain are also expected to enter the detector market Mastering the XFD technology is the key issue which will allow European companies to introduce new innovating systems satisfying evolving user requirements and maintain the market leadership. To counterbalance the non-European competitors, Siemens, Philips and Thomson Tubes Electroniques (world leader in the X-ray detector market) have created a European Joint Venture for the development, production and sale of XFDs for medical industrial and scientific applications: TRIXELL, which is the proposal coordinator.Key contribution to the project will be the basic know-how in XFD microelectronics and in pre-processing electronics developed by TRIXELL, SIEMENS and PHILIPS both with internal R&D projects and European R&D actions. Scintillator materials competence will be brought by the University of Lyon while end user needs (radiologists) / image quality validation will be represented by the Hospital of the Catholic University of Leuven with the support of the marketing department of SIEMENS and PHILIPS Medical Systems. This project is a step forward in image digitisation technology, with a major impact for end-users on diagnostics applications, for the European industrial cooperation and will be a step forward in establishing technologies for high reliability imaging detector devices in the medical industry / Health Care domain.

Funding Scheme

CSC - Cost-sharing contracts


460,Rue Du Pommarin
38430 Moirans

Participants (5)

Katholieke Universiteit Leuven
3000 Leuven
2,Weisshausstrasse 2
52066 Aachen
Philips Medical Systems BV

5680 DA Best
Siemens AG
91301 Forchheim
Université Claude Bernard Lyon 1
43 Boulevard Du 11 Novembre 1918
69622 Villeurbanne