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Flashcards in Sciences Unit 3 SG Deck (25):
1

What is relationship between matrix size and resolution and cost

^matrix size=^resolution=^cost

2

Define matrix

Layout of columns and rows

3

Define pixel

Picture element

4

Define DEL

Detector element
same as pixel but only on DR plate

4

1.What is the result to digital images when there is underexposure
2. What does this look like
3. What does the computer think and do
and how do exposure indicators relate to underexposure

Grainy/sandy/noise
"I'll make it up"
low numbers for Mercy
High numbers for St. L

5

1.What is the result to digital images when there is overexposure
2. What does this look like
3. What does the computer think and do
and how do exposure indicators relate to Overexposure

black/burned out/flat and grey
I'll make it up
High numbers Mercy/Low Stl

6

Advantages/Disadvantages between CR and DR

CR-minimal time savings over F/S
-minimal change in throughput
DR -Increased department throughput
-Increased res
-Higher initial cost

7

Define algorithms and explain what it does for us

Math formula used by computer to manipulate data and process images
It controls density and contrast

8

What factors impact resolution that are unique to digital imaging

Large matrix size increase resolution
Increase # small pictures=increase in res
Decrease IR size=Increase in res
true for IR and monitor

9

What do we call the digital imaging function that fixes minor technique errors

Automatic rescaling
Our fixing of images takes away from dr use

10

What controls the number of photons produced

mAs SSSSSSSS

11

kVp determins what about the beam?
Whats the relationship to scatter production?

Penetrability
Increase in kVp=Decrease in scatter

12

Define brightness

How dark/light and image is

13

Define edge enhancement

increases appearance of sharpness

14

Define DICOM

Allows all vendors equipment to talk to PACS

15

Define SMPTE

Test pattern for brightness

16

Which is best SNR

High, High signal= Low noise

17

Density of digital images when viewing on monitors is called

brightness

18

How does contrast in digital compare to F/S imaging

longer scale digital has longer scale

19

Compare the res of images between CR and DR

DR increased res
CR same as film

20

What is needed to process CR images

Reader

21

CR plates sensitivity to scatter and what that means regarding grid use

More sensitive to scatter so grids are very important with increased kv and thicker patients

22

Most common phosphor used in CR IPs specific name please

Barium, fluoro bromide with europium

23

Rules for more than 1 image on a casette

Don't overlap images
Collimate borders on edges of IR
1 Image on either side of IR
Use lead strips

24

Advantages/disadvantages of direct and indirect image acquisition

CR indirect process becuase you go in room, image is on plate, need to process
DR Poof there's direct process
Faster and higher cost/resolution