Radiology - Image Receptors 1 Flashcards
Type of receptors?
Film and digital
Film is divided into?
Direct and indirect
Digital is divided into?
Solid State sensor and Photostimulable Phosphor
What entails in direct film?
Dental intra-oral. X-rays act directly on silver halide crystals in the film emulsion
What does indirect film entail?
Extra-oral. Light from intensifying screen act on silver halide crystals in film emulsion
Digital receptor of PSP results in?
Latent image produced by interaction of x-rays with phosphor layer on plate. Scanned by laser to produce an image
Difference between phosphor plate and solid state?
PSP tolerated by patients rather than CCD/CMOS.
PSP is sensitive to background radiation.
How does PSP scanner convert to image?
Scanner collects blue light and converts to image
What is the process of PSP to image?
Phosphor layer plate exposed to xray photons -> energy stored in electrons of phosphor crystals -> plate into scanner -> scanned by red laser -> stored energy released as blue light -> Light detected by photodector and sent to digital converter.
Elements of CCD (charge-coupled device)
Back cover, Silicon wafer, scintillator layer and front cover
What does the back cover do?
Incorporate cable to carry signal to PC
What does the silicon wafer do?
Converts light to electrical signal
What does the scintillator layer do?
Converts xray energy to light
Process of CCD…
Xrays hit the scintillator -> light hits the photosensitive cells within the silicon, making the pixels of image -> electrons within the cell released form charge which converts to electrical signal. Then PC converts to image.
What is CMOS?
Complementary metal-oxide semiconductor
CCD vs CMOS
CCD possibly creates better quality than CMOS.
CMOS cheaper to manufacture.
CMOS uses less power.
CCD has been around longer
Adavntage of digital
No chemicals.
Faster processing time.
Easy image transfer.
Disadvantage of digital
Expensive.
Reduction in resolution due to pixel size.
Easily imagine transfer.
What is the possible storage method?
Dental practice.
Local server (PC).
Backup - CD, DVD, hard drive.
What is PACS?
Picture archiving and communication system
Which PSP size of digital receptor is most commonly used?
4 - used for occlusal surfaces
Which ones are used for periapicals and bitewings?
0,1 and 2
Which size used for periapicals anterior adults and all region for children?
0 and 1
Size used for posterior region of mouth for adults?
2
Size zero (0) shouldn’t be used for which part?
Posterior peri-apicals for adults
