The Chart of Death

Question 1

Increasing mAs, only impacts what two things?

Answer 1

Primarily:
-Affects IR Exposure: Increase
-Controls Noise - Decrease (Quantum M.)

Question 2

Time Increase

Answer 2

Primary:
IR Exposure - Increase
Noise - Decrease (Quantum M.)
________________________
Sharpness - Decrease (Motion)

Question 3

kVp Increase

Answer 3

Primary:
IR Exposure - Increase
Subject Contrast - Decrease
Noise - Increase (scatter)

Question 4

Generator Type

Answer 4

From single phase to high frequency, output increases (average kVp). Portable generators have an output that equals the setting.

Question 5

Filtration Increase

Answer 5

Reduces patient exposure

Question 6

Collimation Increase

Answer 6

Primary:
-Affects Subject Contrast: increase
-Controls Noise: Decrease (scatter)

Also:
-Controls IR Exposure: Decrease

Question 7

Part Thickness Increase

Answer 7

Primary:
-Controls IR Exposure: Decrease
-Controls Subject Contrast: Decrease
-Affects Noise: Increase (Scatter)

Also:
-Controls Sharpness: Decrease (OID)
-Affects Size Distortion: Increase (OID)

Question 8

What does pathology impact?

Answer 8

Pathological changes only relate to changes in OID, thickness, or alignment.
__________________________________________
So, if the pathology increases density, it will increase OID, thickness, or alignment.

If the pathology decreases density, it will decrease OID, thickness, or alignment.

Question 9

Scatter increase

Answer 9

-Affects IR Exposure: increase
-Controls Subject Contrast: decrease
-Affect Noise: increase (scatter)

Question 10

Grid Ratio Increase

Answer 10

-Controls IR Exposure: Decrease
-Affect Subject Contrast: Increase
-Controls Noise: Decrease (scatter)

Question 11

Anode-Heel Effect

Answer 11

The beam is weaker on the anode side. Sharpness is higher on the anode side.

Question 12

Focal Spot Size Increase

Answer 12

ONLY controls sharpness: decrease

Question 13

SID Increase

Answer 13

Primary:
-Controls Size Distortion: Decrease

Also:
Controls IR Exposure: Decrease
Affect Sharpness: Increase

Question 14

OID Increase

Answer 14

Primary:
-Controls Sharpness: Decrease

Also:
-Controls IR Exposure: Decrease (Air Gap)y
-Affects Subject Contrast: Increase (Air Gap)
-Controls Noise: Decrease (Scatter)
-Affects Size Distortion: increase

Question 15

SOD Increase

Answer 15

Primary:
-Affect Sharpness: Increase
-Control Size Distortion: Decrease

Question 16

Motion Increase

Answer 16

-Subject Contrast: Decrease
-Affect Noise: Increase (Blur)
-Sharpness: Decrease

Question 17

Alignment Increase

Answer 17

ONLY impacts shape distortion: DECREASE
____________________________________
Nice alignment means minimal shape distortion.

Misalignment would cause shape distortion.

Question 18

Positioning

Answer 18

Positioning changes relate to changes in OID or ALIGNMENT

Question 19

What is the only thing that controls shape distortion?

Answer 19

Increased Alignment.

If tube, patient, or IR are not aligned (decrease) there will be more shape distortion.

If things are perfectly aligned (increase), there will be less shape distortion.

Question 20

What variables primarily control (decrease) size distortion?

________________________________________
What variables affect (increase) size distortion?

Answer 20

Primary controllers:
-Increased SID (decreases magnification THUS decreasing SIZE distortion.
-Increased SOD (Decreases size distortion/magnification)
________________________________________
What affects Size Distortion:
-Increased Part Thickness (would increase OID which also increases size distortion)
-OID (increase if increased. As said above)

Question 21

What variables control (decrease) sharpness?

Answer 21

Primary Controllers (decrease sharpness):
-Increased Focal Spot Size = decreased sharpness.
-Increased OID = decreased sharpness.

Other controllers (decrease sharpness):
-Increased Time = Decreased sharpness (due to motion)
-Increased Motion = Decreased sharpness.
-Increased Part Thickness = Decreased sharpness

Question 22

What variables would increase noise?

Answer 22

Primary:
-kVp increased causes more scatter.
-Park thickness increased causes more scatter.

Also:
-Motion increased: causes more blur which is also noise.
-Scatter increase because duh. It’s noise.

Question 23

What variables would decrease noise?

Answer 23

Primary:
-mA increased (QM)
-Time increased (QM)
-Collimation decreased (scatter)

Also:
-Grid Ratio increased causes decreased noise.
-OID increased causes decrease in scatter aka noise.

Question 24

What variable would PRIMARILY increase subject contrast?

Answer 24

Primary:
-Collimation (If increased causes subject contrast to also increase.)

Question 25

What variables would increase subject contrast?

Answer 25

Primary: -Collimation (if increased, contrast increases) Also: -Grid Ratio (increased grid, increased subject contrast) -OID (increased OID due to Air Gap means increased subject contrast)

Question 26

What variables would PRIMARILY result in a DECREASE in subject contrast?

Answer 26

Primary: -kVp increased, would decrease subject contrast. -Part Thickness increased would decrease subject contrast.

Question 27

What variables would result in a DECREASE in subject contrast?

Answer 27

-Increase kVp (primary) -Increase part thickness (primary) -Increased scatter -Increased motion

Question 28

What are the PRIMARY variables that cause an INCREASE in IR Exposure?

Answer 28

-Increased mA -Increased Time -Increased kVp

Question 29

What are all the variables that cause a DECREASE in IR Exposure?

Answer 29

-Increased Park Thickness (primary) -Increased collimation -Increased grid ratio -Increased SID -Increased OID (due to air gap)

Question 30

if kVp increases, the scale of contrast becomes _______.

Answer 30

longer. (Meaning greyer. Meaning lower contrast meaning the visible difference between 2 areas of brightness is very small.) -Increasing kVp will increase scatter. If there is an increase in scatter, there is a decrease in contrast. Scatter puts a layer of grey over an image.

Question 31

Decrease IR exposure = _________ contrast

Answer 31

Increased contrast

Question 32

Increased Grid Ratio = _______ IR exposure = ________ contrast.

Answer 32

Increased Grid Ration = Decreased IR Exposure = Increased contrast.

Question 33

What has no affect on contrast?

Answer 33

mAs and SID

Question 34

Decreased OID = _______ IR Exposure = ________ contrast.

Answer 34

Decreased OID = Increased IR Exposure = Decreased contrast.

Question 35

Increased collimation = _______ IR exposure = _______ contrast

Answer 35

Increase collimation (make it smaller)= decrease IR exposure= increase contrast

Question 36

Decreased collimation = _______ IR exposure = _______ contrast

Answer 36

Decrease collimation (make it bigger)= increase IR exposure=. decrease contrast

Question 37

Additive Pathology (increases density)= _______ IR exposure= ________ contrast

Answer 37

Additive Pathology (increases density) = decrease IR exposure= increases contrast

Question 38

Destructive Pathology (decreases density)= ________ IR exposure= _______ contrast.

Answer 38

Destructive Pathology (decreases density)= increases IR exposure= decreases contrast

Question 39

When kVp increases what happens to contrast?

Answer 39

Decreases

Question 40

Increasing mAs only affects what factor?

Answer 40

IR Exposure. Increased IR Exposure = Increased mAs.

Question 41

What variables affect (increase) sharpness?

Answer 41

Primary Affect (increase sharpness) -Increased SOD = increased sharpness Also: -Increased SID = Increased sharpness