Digital Imaging

acronyms PSP CRT ADC IP CR DR PACS SNR CNR 10. CCD 11. FOV 12. LUT 13. DICOM 14. RIS 15. HIS 16. TFT 17. DQE

Photostimulable phosphor-europian activated barium fluorohalide (=200 speed) Cathode-ray tube or computer monitor Analog to digital converter Imaging plate computed /digital radiography Picture archiving communication systems

SIGNAL TO NOISE RATIO PG 410 –BUSHONG The higher the signal the less the noise. CONTRAST TO NOISE RATIO can be manipulated until noise becomes too apparent-limited by the SNR Charge coupled device- crystal silicon- small, replaces vidicon in fluoro, device used in DR Field of View –how much of the patient is imaged in the matrix Look up Table – plotting grays on a scale Digital imaging and communications in medicine -blending PACS and other imaging modalities Radiology Information system Hospital Information system

Thin Film Transmitters- indirect conversion detector in DR Thin Film Transmitters- indirect conversion detector in DR. Stores electronic charge (from converted light) before computer processes it. Detective Quantum Efficiency converting x-ray intensities into a radiographic image DAP-Dose Area Product-multiplication of the dose and the area exposed NYQUIST-Sampling frequency of digital data

Computers connected together in a hospital by LAN Outside computers connected to hospital server by VPN

INDIRECT LAYERING FLUORESCENT (ONLY IN INDIRECT-WHY?) PHOTODETECTOR LAYER TFT

AMORPHOUS SILICON-RELEASES ELECTRONS WHEN STRUCK BY LITE (INDIRECT) AMORPHOUS SELENIUM-RELEASES ELECTRONS WHEN STRUCK BY X-RAY PHOTONS (DIRECT)

FOV/MATRIX/PIXEL FOV can increase without change to Matrix or Matrix can change w/o change to FOV – What about the pixel?

Question? Does the pixel size change if the FOV changes and the matrix stays the same? Or what if the matrix changes but the FOV stays the same?

If the FOV increases and the matrix stays the same, the pixel size increases