Radiology 5 & 6. Digital & Film Radiography

Question 1

what are the 2 types of x-ray receptors used in dentistry?

Answer 1

Digital: [Multiple Use]
- phosphor plate
- solid-state sensor

Film: [Single Use]
- Direct action film

Question 2

how is the x-ray shadow converted into an image?

Answer 2

when x-ray beam passes through an object, some of the photons are attenuated (reduced) which leaves a shadow.

The image receptor detects the x-ray shadow and uses it to create an image

Question 3

why are the number of pixels relevant in an x-ray image?

Answer 3

the more pixels = better detail = higher resolution

Question 4

what are the important variables for viewing digital radiographs?

Answer 4

Environment:
- subdued lighting
- avoiding glare

Monitor:
- clean
- Good resolution
- good brightness and contrast

Question 5

what are the types of digital (intra-oral) receptors?

Answer 5

solid-state sensors (wire connected to it, or wireless, image uploaded from the sensor to the pc directly)

phosphor plates (need to be uploaded through a machine to extract the image)

Question 6

why is it important to take care of the receptors for xrays?

Answer 6

if there’s any scratches, tears, fingerprints, bending/creases, it will show up on the image when extracted and compromise the image quality through marks, spots etc

Question 7

what are the main differences between phosphor plates vs solid-state sensors?

Answer 7

Phosphor plates:
- thinner lighter, flexible
- no wires
- image needs to be processed in scanner
- similar handling to film

Solid-state sensor:
- Bulkier & rigid
- smaller active area
- wired usually
- Usually wired
- more expensive

Question 8

what is the use of an intra-oral film packet?

Answer 8

it acts to protect the film from light exposure, damage by fingers & saliva

Question 9

what is the film speed and what does it mean?

Answer 9

relates to the amount of x-ray exposure required to product an adequate image

higher speed -> less radiation required to achieve an image

Question 10

what are the advantages of digital radiography?

Answer 10

• no need for chemical processing
• easy storage, all digital
• images can be integrated in patient records
• transferring of images is easy
• images can be manipulated on the pc

Question 11

what are the disadvantages of digital radiography?

Answer 11

• if its poor resolution -> risk of pixelation
• needs a special computer for optimal viewing
• risk of data loss/corruption