James Anthony Seibert PhD, Presenter: Nothing to Disclose

1) Describe the fundamental components of CCD/CMOS-based DR detectors. 2) Highlight the similarities and differences between the various detector configurations (fiber-optic coupler vs. lens, CCD vs CMOS). 3) Describe the physical reasons for imaging performance. 4) Survey commercial offerings in the CCD/CMOS-based technologies.

Charge-coupled-device (CCD) and Complementary Metal Oxide Semiconductor (CMOS) sensors have widespread use in various applications of consumer-grade and scientific grade electronics. CCD cameras have been used for medical imaging applications for quite some time, first as “camera-on-a-stick” devices for early teleradiology efforts, for replacement of TV cameras on fluoroscopy systems, in small field of view (FOV) digital stereotactic breast biopsy systems, and large FOV systems for general radiography. CMOS sensors are more recent, with similar and dissimilar attributes compared to CCD for design, readout, and noise properties. This presentation describes the technology and function of CCD and CMOS sensors, including signal readout methods and noise properties. Fundamental components comprising a digital radiography system include an x-ray to light scintillator, optical coupling, and the photo-sensor itself. Optical coupling choices are direct, fiber-optic taper, and lens optical coupling. For large FOV designs, image demagnification is necessary for small-area sensors, usually requiring the use of lenses. Inadequate light collection efficiency of the lens can be the governing statistical process (secondary quantum sink) in the output signal. Corrections for lens aberrations and geometric distortions, as well as protection from direct ionizing radiation are necessary for CCD sensors. However, modularity of the detector design reduces system costs and allows easier sub-component repairs. CMOS sensors have the flexibility to be butted together into a large detector area with micro-lens arrays for good light collection efficiency, but high electronic noise in the readout process can limit imaging capabilities. Technological advances continue, and detective quantum efficiency is approaching that of other large FOV digital detectors. A survey of the commercial offerings for CCD and CMOS based imaging detectors available in 2005 concludes the presentation.

Seibert, J, CCD/CMOS-based Acquisition Technologies.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4402536.html