Authors: Martin Spahn
Publish Date: 2005/04/02
Volume: 15, Issue: 9, Pages: 1934-1947
Abstract
Diagnostic and interventional flat detector Xray systems are penetrating the market in all application segments First introduced in radiography and mammography they have conquered cardiac and general angiography and are getting increasing attention in fluoroscopy Two flat detector technologies prevail The dominating method is based on an indirect Xray conversion process using cesium iodide scintillators It offers considerable advantages in radiography angiography and fluoroscopy The other method employs a direct converter such as selenium which is particularly suitable for mammography Both flat detector technologies are based on amorphous silicon active pixel matrices Flat detectors facilitate the clinical workflow in radiographic rooms foster improved image quality and provide the potential to reduce dose This added value is based on their large dynamic range their high sensitivity to Xrays and the instant availability of the image Advanced image processing is instrumental in these improvements and expand the range of conventional diagnostic methods In angiography and fluoroscopy the transition from image intensifiers to flat detectors is facilitated by ample advantages they offer such as distortionfree images excellent coarse contrast large dynamic range and high Xray sensitivity These characteristics and their compatibility with strong magnetic fields are the basis for improved diagnostic methods and innovative interventional applicationsThe author would like to thank Prof G Marchal University Hospitals Leuven Belgium for providing the radiographic images The mammograms are courtesy of Dr R SchulzWendtland University of Erlangen Germany Dr R Meese Mother Frances Hospital Tyler Texas USA provided the case using magnetic navigation techniques Also special thanks goes to Dr P Bernhardt who provided the simulated data on quantum efficiencies and to Dr T Mertelmeier for his suggestions and availability for fruitful discussions
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