Digital image

Question 1

What are the three steps in digital radiographic imaging?

Answer 1

1. Electronic measurement of the x-ray pattern
2. Conversion of electonic measurement into computer file
3. Viewing that file on a compute monitor

Question 2

DICOM stands for what and carries with it what?

Answer 2

Digital imaging and communication in medicine

carries with it metadata tags or information about the image, time, patient, etc.

Question 3

How big is a normal DICOM file with a radiographic image?

Answer 3

4-12 MB per image

Question 4

The number of possible gray shades is referred to as what?

Answer 4

Bit depth

Question 5

What does pre-processing mean?

Answer 5

It is the corrections the manufacturer applies to the raw data. It is out of our control.

Question 6

What does processing step mean?

Answer 6

Taking the corrected raw data and turning it into a radiograph.

Pre-sets are in these regions.

Question 7

What does post-processing step mean?

Answer 7

All under my control - In radiant.

Question 8

As ambient light increases, the perceived what decreases?

Answer 8

The perceived difference between light and dark.

Question 9

Why are LCDs with high contrast ratio so expensive?

Answer 9

LCDs rely on backlighting and therefore true black is technically challenging…. therefore high scontrast ratios are more expensive.

Question 10

What modality has the highest spatial resolution?

Answer 10

Screen film.

Question 11

What is the advantage of digital radiographs?

Answer 11

1. Contrast optimization (post processing) - Assigning different grayscales to different portions of the radiograph
2. Exposure latitude - Ability to compensate for inappropriate