Exam 1.2: Digital X Rays

Question 1

What are some advantages of Digital X Rays

Answer 1

Less exposure: Endo
Speed of image acquisition
Image manipulation
Electronic Records
Ease of viewing
No darkroom/chemicals

Question 2

What are some disadvantages of Digital X-rays

Answer 2

Cost
Sensor dimension and cords
Infection control
Lack of standardization
Medicolegal

Question 3

What are the two main digital systems?

Answer 3

Direct (Electronic Sensors)

Semi-Direct (Photostimulable Phosphor Plates)

Question 4

How do direct sensors capture the image?

Answer 4

Sensor captures radiation and transfers signal directly to computer

Question 5

How does the Semi direct PSP capture the image

Answer 5

Plates are irradiated producing a latent image in phosphor crystals

Laser scan then transfers image to CPU

Question 6

What is a drawback when using direct sensors on premolar BWs and PAs

Answer 6

Can’t capture D of canine and M of 1st PM

Question 7

What are the advantages of Direct Sensors over PSPs

Answer 7

Instant image on screen

If sensor is still in place, you can adjust and retake image

Question 8

What are advantages of PSPs

Answer 8

Accurate positioning
Durable
Flexible
More sizes available
Lower replacement costs
More comfortable

Question 9

What is the range of available films

Answer 9

14-20 lp/mm

Question 10

What is the resolution limit for the human eye

Answer 10

~11 lp/mm

Question 11

What do you sacrifice when you increase resolution?

Answer 11

Contrast

Question 12

What is the goal of DICOM

Answer 12

Try to get universal file formats that allow different software to recognize and transfer digital images seamlessly

Question 13

What does PACS stand for?

Answer 13

Picture Archiving & Communications System

Question 14

What are some practical concern for your private practice regarding digital xrays

Answer 14

Centralized storage and dedicated off site backup

DICOM conformity

Image appearance

HIPPA & Data encryption