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d i u d c L he choice of diagnostic display onitors was relatively straightforard for early adopters of picture rchiving and communication sysems. Hardware was of a single ype, cathode ray tube (CRT) techology, and was usually oriented in ortrait mode, emulating the shape f film. Monitors had high brightess, typically 60 to 100 foot-lamerts (FL), relative to other comuter and television monitors and igh refresh rates of greater than 72 z to reduce flicker visible to the uman eye. The devices themselves ere physically large, heavy, and xpensive. They generated noticeble quantities of heat while conuming relatively high amounts of ower, and their display quality deraded quickly, requiring frequent onitor replacement. Early medical-grade monitors ere available in two spatial resoutions (high and low) reflecting heir pixel matrix sizes (2K, or 048 columns by 2500 rows; and K, or 1024 columns by 1280 colmns, respectively). Medium-resoluion 1.5K monitors of 1500 columns y 1500 rows were later added to the ix. Because of the exponentially igher cost of 2K monitors comared with 1K monitors, radiology epartments typically had a combiation of a few strategically placed igh-resolution displays and many ow-resolution or medium-resoluion displays. The ACR recomended that 2K monitors be used or primary diagnosis of digital proection radiographs because a single mage could be displayed per montor in its full inherent acquired spaial resolution. The cross-sectional odalities with slice matrix sizes of 12 512 for computed tomograp

In the DEPFET pixel concept the detected incident radiation is directly sensed and amplified by a JFET integrated in every pixel cell. While the DEPFET detector principle has already been demonstrated previously on single pixel structures, we present here the first successful operation of a large 32×32 DEPFET pixel matrix as an imaging device. The matrix has been exposed to 60 keV gamma rays of a 241 Am source and has been scanned using an IR laser. The principle of operation as well as the charge collection in the structure and possible improvements are discussed.

A new kind of silicon pixel detector with integrated amplification has been built and tested. Each pixel consists of a p -channel JFET located on a fully depleted substrate. The pixel size can be customized by using a drift-chamber-like transport mechanism in each pixel. The homogeneity of the signal response of a small matrix was investigated with a laser diode. The measured rise time and gain of the device are analyzed with a simple small signal model.