Digital Radiography Revealed

The digital imaging market spaces are mostly serviced by charge-coupled device (CCD), complementary metal-oxide semiconductor (CMOS), and flat panel image sensor technologies. CMOS Active Pixel Sensor (APS) technology has emerged recently to offer a cost and performance advantage over both CCD and TFT technologies in many radiography applications. Fundamental design considerations for CMOS X-ray image sensor technologies include the concept that image resolution is not a direct function of the pixel size. CMOS APS pixel design enables the cancellation of voltage offsets and reduction of random noise from the sensor output by sampling and subtracting background signal from imaged signal. It is projected that the CMOS APS radiographic sensor technology will offer improved dynamic range, resolution and signal to noise performance over competing large area X-ray sensor technologies at a better price per centimeter squared of detector area.