MAS is _____ proportional to pt. dose
Directly
KVP is main controlling factor of __1__ but it also affects density mainly because it controls __2__.
2. Scatter
Inverse Square Law:
If you double the distance, you cover __1__ the area with __2__ the intensity. If you cut distance in half, you cover __3__ the area with __4__ the intensity.
30% rule deals with
MAS
15% rule deals with
KVP
30% rule states in order to make visible change in __1__ one must increase or decrease __2__ by 30%
2. MAS
15% Rule: BELOW 90 kV 1. +10 kV=\_\_\_\_\_\_\_ 2. -10 kV=\_\_\_\_\_\_\_ ABOVE 90 kV 3. +15 kV=\_\_\_\_\_\_\_ 4. -15 kV=\_\_\_\_\_\_\_
Increase OID=______ density
DECREASED (due to air gap and scatter bypassing IR)
Increased screen speed= 1. MAS 2. Pt. Dose 3. Detail Decreased screen speed: 4. MAS 5. Pt. Dose 6. Detail
Increased collimation=_____ density
Decrease
Decreased collimation=______ density
Increased
As part density increases, IR density __1__. As part density decreases, IR density (RE) __2__.
2. Increases
Degree of differences in density
Contrast
High kV:
Low kV:
Increased grid ratio= __1__ contrast ( __2__scatter)
2. Less
Decreased grid ratio=__1__ contrast ( __2__ scatter)
2. More
Increased collimation=__1__ contrast.
Decreased collimaton=__2__ contrast
2. Decreased
Additive pathology requires what in technique?
Increase
Destructive pathology requires what in technique?
Decrease
3 geometric factors that control recorded detail:
1.
2.
3.
As FS increases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
2. Decreases
As FS decreases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
2. Increases
As SID increases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
2. Increases