An examination requires 80 mAs at 180cm SID. If the distance is changed to 90cm SID what should be the new mAs setting?
A grid is made with interspace material that is 600um thick. The height of the grid is 6000um. What is the grid ratio?
Which of the following grid errors would result from an improperly positioned grid?
Upside down grid
Off level grid
Off focus grid
Off level grid
Scatter increases with which of the following? Choose all that apply.
Large field size
Large field size, large patients, high kvp
True or false. Scatter increases contrast on an image
The ability of a system to distinguish between similar tissues is called:
And underexposed radiograph would have _______ optical density.
Match the description with the correct beam restriction device: Field size is determined by the distal end of the structure
Cones and cylinders
Match the description with the correct beam restriction device: Has a fixed lead opening and consistent SID
Match the description with the correct beam restriction device: Has the most efficient beam restriction
True or false. The fixed KVP/variable mAs technique chart will provide more adequate penetration of the part then the variable KVP/fixed mAs.
Does collimation increase or decrease patient dose?
Does collimation increase or decrease contrast?
Does collimation increase or decrease density?
When filtration is added will scatter increase or decrease
When filtration is added does the quality of the beam increase or decrease
When filtration is added does image contrast increase or decrease
True or false: the heart and thoracic spine of a chest x-ray would have a higher optical density than the lung fields.
The density control settings (+2, -2, +1), adjust what with each number?
The exposure time
Collimators help control radiation produced at a location other than the focal spot. This is called:
What technique chart would typically produce an image with a shorter scale of contrast?
Variable kvp/ fixed mAs
Exposure technique charts are based on what?
The thickness of the anatomic part
Which grid has the ability to clean up the most scatter and has the highest patient dose?
The number grid strips per centimeter is known as:
The pivot point about which the x-ray tube and IR move in tomography is called the:
What controls the number of x-rays produced
Which of the following conditions would require a decrease in technique?
Which of the following types of x-rays contribute to forming the image? Choose all that apply
1.X-rays that interact with the patient and are absorbed
2.X-rays that arrive at the IR and are transmitted without interacting
3.X-rays that are scattered in th
2 and 3
An increase in mAs would result in an increase or decrease in optical density?
An increase in SID would result in an increase or decrease in optical density?
An increase in collimation would result in an increase or decrease in optical density?
How does KVP affect the contrast of an image? An increase in KVP causes a ___________ in contrast.
Which of the following factors must increase when using the airgap technique? Check all that apply.
1, 3 and 4
Which of the following is not a prime exposure factor?
You x-ray a patient and the anatomical part requires 120 KVP. Which grid ratio would be appropriate?
Mobile imaging uses _______ ratio grids.
__:__ is satisfactory for <90 kVp
8 to 1
__:__ is recommended for exams >100kVp
16 to 1
General fixed equipment uses __:__ or __:__
10 to 1 or 12 to 1
Grid strips made out of ___________ material.
Interspace material made out of _____________ material.
True or false: aluminum absorbs more primary x-rays
True or false: plastic fiber interspace material has a lower patient dose
True or false: aluminum material requires a higher mAs
True or false: grid interspace material is radiopaque
During magnification radiography, the OID increases while the ________ remains constant.
You are attempting to x-ray a patient who cannot hold still and needs to use a short exposure time. Which factor needs to be increased as a result of this shorter exposure time?
True or false: during tomography, a larger angle creates a thicker slice of anatomy.
Located in front of the IR so that radiation interacts with the detector before interacting with the IR
An exit type of device that measures radiation after it passes through the IR
The sharpness or detail of an image is measured by:
True or false: mAs is the main factor that controls optical density
An image with a lot of shades of gray would be:
When a grid is used does contrast increase or decrease?
Which factor is increased when using a grid to maintain adequate density?
Situation: artifact produced by an improperly positioned radiographic tube.
NOT by an improperly positioned grid.
Results in.... grid cutoff across entire image, underexposed image (low OD), light image
A tilted IR under a patient will result in a Off-_______ grid.
Grid positioned correctly.
Central ray is not centered to grid.
Problem with focused grids.
Center of focused grid must be positioned directly under x-ray tube target.
Grid cut off across entire image.
Underexposed image (low OD)
Problem with focused grids.
Radiographs taken at SIDs unspecified for that grid.
The farther the grid is from the specified focal distance, the more severe the grid cutoff. Positioning at proper SID more important with high ratio grids (less ex
Most common : grid is both off _________ and off _________.
What grids are the most common in diagnostic radiography?
Higher ratio grids result in higher or lower patient dose?
mAs is increased ___% for every cm of air gap.
Air gap = Equivalent to using an __:__ grid.
8 to 1
air gap technique is not affective with ____ kVp
Airgap technique is only useful at ____ kVp and below because most scatter radiation is side scatter.
What controls contrast?
Key factor that controls OD
Longer SID = _________ spatial resolution
added filtration = _________ scatter and __________ image contrast.
An increase in KVP will result in a _________ in contrast
An increase in grid ratio will result in a __________ in contrast.
An increase in beam restriction will result in an ___________ in contrast.
An increase in milliampere seconds will result in an ____________ in contrast.
Magnification radiography increases patient radiation dose by about ___x normal dose because grids are not used.