Author/Authors :
Babichev، نويسنده , , E.A. and Baru، نويسنده , , S.E. and Khabakhpashev، نويسنده , , A.G. and Kolachev، نويسنده , , G.M. and Neustroev، نويسنده , , V.V. and Pestov، نويسنده , , Yu.N. and Ponomarev، نويسنده , , O.A. and Savinov، نويسنده , , G.M. and Shekhtman، نويسنده , , L.I. and Martinez-Davalos، نويسنده , , A. and Speller، نويسنده , , R.D. and Miller، نويسنده , , D.J.، نويسنده ,
Abstract :
Application of MultiWire Proportional Chambers (MWPC) and MicroStrip Gas Chambers (MSGC) in medical radiography is discussed. These detectors are capable of detecting X-rays in counting mode with high efficiency, thus giving essential dose reduction compared to film/screen techniques. This was demonstrated on several Digital Radiographic Devices (DRD) with one-dimensional MWPC and scanning in the orthogonal direction. Effective pixel sizes of 1 mm and 0.5 mm for different devices with highly parallel readout systems has been achieved. The counting rate capability of DRDs is ∼ 500 kHz/pixel, which is enough to get high statistics of X-rays with a short exposure. Dose saving factors from 1 to 2 orders of magnitude for several common examinations were demonstrated.
r development of this approach can be made with MSGC which reproduce operation of MWPC in a much smaller scale. First tests of prototype chambers with 200 μm pitch of strips at high pressure have shown the possibility to reach a gain of ∼ 104 in a 6 bar Xe mixture. A proper choice of substrate material permits one to avoid charging problems at high fluxes. These features allow, one to build a counting device with 0.2 mm pixels for the detection of X-rays of 20–60 keV.
