Radiology - Image Receptors 1

Question 1

Type of receptors?

Answer 1

Film and digital

Question 2

Film is divided into?

Answer 2

Direct and indirect

Question 3

Digital is divided into?

Answer 3

Solid State sensor and Photostimulable Phosphor

Question 4

What entails in direct film?

Answer 4

Dental intra-oral. X-rays act directly on silver halide crystals in the film emulsion

Question 5

What does indirect film entail?

Answer 5

Extra-oral. Light from intensifying screen act on silver halide crystals in film emulsion

Question 6

Digital receptor of PSP results in?

Answer 6

Latent image produced by interaction of x-rays with phosphor layer on plate. Scanned by laser to produce an image

Question 7

Difference between phosphor plate and solid state?

Answer 7

PSP tolerated by patients rather than CCD/CMOS.

PSP is sensitive to background radiation.

Question 8

How does PSP scanner convert to image?

Answer 8

Scanner collects blue light and converts to image

Question 9

What is the process of PSP to image?

Answer 9

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.

Question 10

Elements of CCD (charge-coupled device)

Answer 10

Back cover, Silicon wafer, scintillator layer and front cover

Question 11

What does the back cover do?

Answer 11

Incorporate cable to carry signal to PC

Question 12

What does the silicon wafer do?

Answer 12

Converts light to electrical signal

Question 13

What does the scintillator layer do?

Answer 13

Converts xray energy to light

Question 14

Process of CCD…

Answer 14

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.

Question 15

What is CMOS?

Answer 15

Complementary metal-oxide semiconductor

Question 16

CCD vs CMOS

Answer 16

CCD possibly creates better quality than CMOS.
CMOS cheaper to manufacture.
CMOS uses less power.
CCD has been around longer

Question 17

Adavntage of digital

Answer 17

No chemicals.
Faster processing time.
Easy image transfer.

Question 18

Disadvantage of digital

Answer 18

Expensive.
Reduction in resolution due to pixel size.
Easily imagine transfer.

Question 19

What is the possible storage method?

Answer 19

Dental practice.
Local server (PC).
Backup - CD, DVD, hard drive.

Question 20

What is PACS?

Answer 20

Picture archiving and communication system

Question 21

Which PSP size of digital receptor is most commonly used?

Answer 21

4 - used for occlusal surfaces

Question 22

Which ones are used for periapicals and bitewings?

Answer 22

0,1 and 2

Question 23

Which size used for periapicals anterior adults and all region for children?

Answer 23

0 and 1

Question 24

Size used for posterior region of mouth for adults?

Answer 24

2

Question 25

Size zero (0) shouldn’t be used for which part?

Answer 25

Posterior peri-apicals for adults