Digital Imaging

acronyms 1.PSP 2.CRT 3.ADC 4.IP 5.CR 6.DR 7.PACS 8.SNR 9.CNR 10. CCD 11. FOV 12. LUT 13. DICOM 14. RIS 15. HIS 16. TFT 17. DQE 18. DAP 19. DEL 20. Voxel

1.Photostimulable phosphor-europian activated barium fluorohalide (=200 speed) 2. Cathode-ray tube or computer monitor 3.Analog to digital converter 4.Imaging plate 5.computed 6./digital radiography 7.Picture archiving communication systems

8.SIGNAL TO NOISE RATIO PG 410 –BUSHONG The higher the signal the less the noise. 9.CONTRAST TO NOISE RATIO can be manipulated until noise becomes too apparent-limited by the SNR 10.Charge coupled device - crystal silicon- small, replaces vidicon in fluoro, device used in DR 11.Field of View – how much of the patient is imaged in the matrix 12.Look up Table – plotting grays on a scale 13.Digital imaging and communications in medicine -blending PACS and other imaging modalities 14.Radiology Information system 15.Hospital Information system

16.Thin Film Transmitters- indirect conversion detector in DR. Stores electronic charge (from converted light) before computer processes it. 17.Detective Quantum Efficiency converting x-ray intensities into a radiographic image 18.DAP- Dose Area Product-multiplication of the dose and the area exposed 19, DEL- Detector Element. -size of the TFT..smaller-better resolution 20. Voxel-tissue volume 16.NYQUIST-Sampling frequency of digital data

20.Voxel-tissue volume X,y and z lines NYQUIST-Sampling frequency of digital data Z line X line y line

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