Sciences Unit 3 SG Flashcards
What is relationship between matrix size and resolution and cost
^matrix size=^resolution=^cost
Define matrix
Layout of columns and rows
Define pixel
Picture element
Define DEL
Detector element
same as pixel but only on DR plate
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
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
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 costDefine algorithms and explain what it does for us
Math formula used by computer to manipulate data and process images
It controls density and contrast
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
What do we call the digital imaging function that fixes minor technique errors
Automatic rescaling
Our fixing of images takes away from dr use
What controls the number of photons produced
mAs SSSSSSSS
kVp determins what about the beam?
Whats the relationship to scatter production?
Penetrability
Increase in kVp=Decrease in scatter
Define brightness
How dark/light and image is
Define edge enhancement
increases appearance of sharpness
Define DICOM
Allows all vendors equipment to talk to PACS
Define SMPTE
Test pattern for brightness
Which is best SNR
High, High signal= Low noise
Density of digital images when viewing on monitors is called
brightness
How does contrast in digital compare to F/S imaging
longer scale digital has longer scale
Compare the res of images between CR and DR
DR increased res
CR same as film
What is needed to process CR images
Reader
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
Most common phosphor used in CR IPs specific name please
Barium, fluoro bromide with europium
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
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
