Quality and Quantity PowerPoint Part 1

Milliamperage measures _______________.

tube current

A __________ is the measure of electrostatic charge.

Coulomb (1 Coulumb = 6.25 x 10 ^18 e-)

Intensity is proportional to _______.

kVp^2

What is the formula used to find intensity when technique is changed?

I1/I2= (mAs1/mAs2)(kVp1/kVp2)^2

X-ray quantity is _________ proportional to the square of the distance from the source.

inversely

For quantity and distance, you use the _________.

inverse square law, I1/I2= (d2/d1)^2

What is the exposure maintenance formula?

New mAs/ Old mAs = (New Distance/ Old Distance)^2

Filters _______ the beam and ________ low energy photons.

harden, reduce

___________ determines the number of photons in the x-ray beam.

Milliamperage (mA)

Is milliamperage quality or quantity?

quantity

For how long the electrons travel across the tube is considered the ________.

time (s)

Is time considered quality or quantity?

quantity

the formula for mAs is:

milliamperage x seconds

_______ determines the energy of the x-ray beam.

kVp

Is kVp considered quality or quantity?

quality mostly, but also plays a role in quantity

________ is the distance from the X-ray tube to the film.

SID (source to image distance)

___________ is the distance from the X-ray tube to the part being examined.

SOD (source to object distance)

___________ is the distance from the part being examined to the IR. You should limit this whenever possible.

OID (object to image distance)

What are the prime controlling factors?

mA-quantity

Time-quantity

kVp- quality

Describe Quantity.

-the number of x-rays produced

-controlled by mA and time

Describe Quality.

-penetrability of x-rays

-controlled by kVp

Quantity is measured in _____ or ____.

mGya or mR (milli-roentgen)

Quantity can be called radiation exposure, x-ray quantity, or _________.

x-ray intensity

What 4 factors affect quantity?

1. mAs

2. kVp

3. distance

4. filtration

At a specific _____ there is a specific amount of ________ applied to the filament.

mA, current

After mA is applied, _____________ occurs and a __________ is created.

thermionic emission, space charge

________________ measures the length of exposure in seconds. (sometimes milliseconds)

exposure time

Exposure time is _________ proportional to tube current, and has a ___________ relationship with IR exposure.

directly, direct

Quantity is ______ proportional to mAs

directly

What is the formula for the relationship between intensity and mAs?

I1/I2 = mAs1/mAs2

______ is not the primary controller of exposure, but does have an effect.

kVp

What is the kVp/ Intensity formula?

I1/I2 = (kVp1/kVp2)^2

Doubling the kVp increases the intensity by ______.

4

Increasing the kVp by _____% has the same effect in IR exposure as ___________ mAs.

15%, doubling

On film, changing _______ changes contrast, so it is not the primary controlling factor for exposure.

kVp

On digital, _______ does not change contrast when using the _________.

kVp, 15% rule (this saves patient dose!)

When using digital you are able to use higher _______ and lower _______. This can save patient dose.

kVp, mAs

Doubling the distance reduces the intensity by a factor of____.

4

The ________________ formula is used to calculate the new mAs when SID changes.

Exposure Maintenance

Filters reduce________, but increase _________.

quantity, quality

Filtration functions to _______ patient dose.

reduce

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