A flat X-ray detector with lead oxide (PbO) as direct conversion material has been developed. The material lead oxide, which has a very high X-ray absorption, was analysed in detail including Raman spectroscopy and electron microscopy. X-ray performance data such as dark current, charge yield and temporal behaviour were evaluated on small functional samples. A process to cover a-Si TFT-plates with PbO has been developed. We present imaging results from a large detector with an active area of 18 x 20 cm(2). The detector has 1080 x 960 pixels with a pixel pitch of 184 mum. The linearity of detector response was verified. The NPS was determined with a total dark noise as low as 1800 electrons/pixel. The MTF was measured with two different methods: first with the analysis of a square wave phantom and second with a narrow slit. The MTF at the Nyquist frequency of 2.72 lp/mm was 50 %. We calculated first DQE values of our prototype detector plates. Full size images of anatomic and technical phantoms are shown.
PbO as direct conversion X-ray detector material / M., Simon; R. A., Ford; A. R., Franklin; S. P., Grabowski; B., Menser; G., Much; Nascetti, Augusto; M., Overdick; M. J., Powell; D. U., Wiechert. - 5368:1(2004), pp. 188-199. (Intervento presentato al convegno Medical Imaging 2004 Conference tenutosi a San Diego, CA nel FEB 17-19, 2004) [10.1117/12.533010].
PbO as direct conversion X-ray detector material
NASCETTI, Augusto;
2004
Abstract
A flat X-ray detector with lead oxide (PbO) as direct conversion material has been developed. The material lead oxide, which has a very high X-ray absorption, was analysed in detail including Raman spectroscopy and electron microscopy. X-ray performance data such as dark current, charge yield and temporal behaviour were evaluated on small functional samples. A process to cover a-Si TFT-plates with PbO has been developed. We present imaging results from a large detector with an active area of 18 x 20 cm(2). The detector has 1080 x 960 pixels with a pixel pitch of 184 mum. The linearity of detector response was verified. The NPS was determined with a total dark noise as low as 1800 electrons/pixel. The MTF was measured with two different methods: first with the analysis of a square wave phantom and second with a narrow slit. The MTF at the Nyquist frequency of 2.72 lp/mm was 50 %. We calculated first DQE values of our prototype detector plates. Full size images of anatomic and technical phantoms are shown.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
