Rad Quality 4
Which of the following would be used to minimize magnification? -
1 &3 (smallest OID possible ,longest SID)
Spatial resolution increases with how many blurs?
3
MF= SID/SOD whats the answer? SID=40 OID=10
40(SID) - 10(OID)= 30(SOD) 40/30= 1.3MF
What is the formula for magnification factor?-
All 3
Focal spot decreases with _______??
All of the above
What happens with geometric unsharpness? ______??
All of the above
Control motion=_________?
All of the above.
What needs to increase to improve radiographic image quality? -
Increase SID (longest SID possible)
When you decrease the tube angle, shape distortion will be ___more or less_____.
Less
What are two ways to minimize magnification?
Long SID, Small OID
What are the formulas for Magnification Factor?
MF= object size (OS)/ image size(IS) MF=SID/SOD
________SID and _______ magnification. *______related.
More SID, less magnification. Less SID, more magnification. INVERSELY
Resolution improves when _____ decreases.
OID
Resolution is improved with? -
OID decreases, increasing your SID
What is used to minimize magnification? -OID -SID -Focal Spot
ONLY OID & SID
How do you reduce distortion?
Place the image and IR parallel to IP
Resolution improves when _____ increases.
SID
What do you increase to improve image quality?
SID
True/False: Overall magnification is not distortion.
True
True/False: Unsharpness is NOT effected by kVp.
True
Which of the following may be used to control motion during a radiographic examination?
all 3 (shortest time possible, precise instructions to pt., immobilization devices)
Geometric un sharpness decreases as? -
all of them
As focal spot size decreases-
all of these
Which of the following can be done to help compensate for an angled part? -
angle the tube and the IR
What two things can you do to compensate for part angulation?
angle tube and IR
Degree of resolution______?
bony trabecular pattern
When evaluating the degree of resolution on an actual radiograph image an effective image tissue to analyse is?
bony trabecular patterns
The best method for controlling motion when the patient is unable to cooperate is to? -
decrease your time, while maintaining same mAs
Factors affecting recorded detail include? -
focal spot size
What factor effects recorded detail?
focal spot size
What happens to your image when your part is not lined up to CR?
foreshortening
Which one of the following occurs when the part is improperly aligned with the CR? -
foreshortening, (or elongated)
Materials with ______ will attenuate more x-rays.
high atomic #
When OID increases, magnification ________.
increases
What motion always has a negative impact?
involuntary motion
Which of these can negatively impact recorded detail? -
involuntary motion
Unsharpness is not affected by which of the following? -
kVp
An examination of body parts with large inherent OID warned a ________ whenever possible? -
larger SID
The greater the SID the -
less magnification
when improving radiographic quality you want to use long _____possible, and use short _____ possible.
long SID and short OID
What is the best way to reduce magnification? -
long SID, small OID
What happens if you increase your OID? -
magnification increases
The three primary geometric factors affect image quality are? -
magnification, distortion, focal spot size
What are the 3 geometric factors?
magnification, distortion, focal-spot blur
Whats the best method to control motion?
maintain mAs by decreasing time
What do you do with your CR when you want to reduce distortion?
make CR parallel to IR
How do you compensate for an exam with lots of OID?
make more SID
Which of the following human immobilizers is used to keep the patient in position while the following people are available? -
male relative to hold
Xray beam is divergent which means ______ is impossible.
minification
Because x ray beam is divergent-
minification is impossible
What is the formula for object size?
object size= image size (SOD/SID)
what are the factors that effect distortion?
object thickness, object position, object shape
What effects subject contrast? -
patient thickness
Proper alignment ___________?
perp and perp
Properly alignment is achieved when the CR is ______ to the part and ______ to the IR. -
perpendicular, perpendicular
What effects subject contrast?
pt thickness
Patient thickness affects image quality by which things? -
radiographic contrast, magnification, and focal spot
Pt thickness effects quality by effecting what 3 things?
radiographic contrast, magnification, focal spot blur
Motion of pt, xray tube or IR reduces __________.
radiographic quality
What radiographic qualities determine sharpness? (2)
recorded detail & distortion
Which of the following radiographic qualities determine the sharpness of detail in a finished radiograph? -
recorded detail & distortion
Increasing SID does what things?
reduce magnification, improve spatial resolution, reduce pt dose
When the pt is reversed what do you do to the tube?
reverse
If the position of the patient is reversed, the direction of the tube angle must be _______ to maintain the same relationship. -
reversed
If you decrease your tube angle which of the following will occur? -
shape distortion will decrease
Distortion is the best representation of? -
size & shape
Distortion is a misrepresentation of ________ &________.
size and shape
___focal spot size reduces penumbra
small
What effects shape distortion?
tube angulation
What is the correct name for the loss of recorded detail due to the use of a large focal spot? -
unsharpness
________-loss of recorded detail due to large focal spot.
unsharpness
What do you use when you want to reduce focal spot blur?
use smallest focal spot
How do you reduce focal spot blur? -
using smallest focal spot as possible
Which of the following affects shape distortion? -
x-ray tube angulation
