Exam II Flashcards
If you make an exposure at 100 mAs with 80 kV and the radiographic density is good, what would be the outcome if you x-rayed the same part of the same person a second time with 50 mAs and 92 kV?
The first film would have the higher contrast
What is undesirable with magnification distortion?
A. Object altered in shape
B. Borders of object will be blurred
C. Borders of object will be darker
D. Object will appear smaller
B. The borders of the object will be blurred
What is the outcome of reducing the mAs by 1/2 and keeping the kV and the distance constant?
The film density would be decreased
With which percentage in mAs would yo uexpect to see the slightest change in radiographic density?
30%
If you took 4 A-P lumbar films, the first with 95 kV and 6.25 mAs, the second with 106 kV and 3.75 mAs, the third with 58 kV and 60 mAs and the fourth at 85 kV and 8 mAs, which would have the lowest contrast?
The second film
Osteoporosis will usually require you to do which of the following?
A. Reduce tube output
B. Increase tube output
C. Develop films faster
D. Pump up the patient
A. Reduce the tube output
Which of the following would produce the same film density as 200 mA for 0.5 seconds?
A. 300 mA for 1.5 sec
B. 250 mA for .75 sec
C. 150 mA for 2 sec
D. 100 mA for 1 sec
D. 100 mA for 1 second``
To double the density of a filming using kV, what would you do?
Increase kV by 15%
If you compared 2 radiographs of a cervical spine with one having been taken at 40” and the other at 72” with the appropriate change in the radiographic technique, what would you find?
The 72” film will have a smaller and clearer image, while the 40” film will be larger and less clear
Which of the following could be a problem if your x-ray tube was laterally shifted from the center of the film?
A. Magnification distortion
B. Shape distortion
C. Image blurring
D. Unequal filtration
B. Shape distortion
The number of electrons will be doubled if what happens?
Increasing the mAs by 2 times
Which is true about the air-gap technique when normally used in a cervical spine series?
A. It makes the vertebra appear larger
B. It requires a longer tube distance
C. It usually doesn’t require the use of a grid
D. It is best used with the A-P cervical film
C. It usually doesn’t require the use of a grid
The higher the kVp, the more _____ radiation is produced.
Compton’s
What is the range of body part thickness when a grid should first be considered advantages to use?
10-15cm
If you wanted a film with more blacks and whites and less gray, what would you do?
Use a low kV and high mAs technique
Which of the following is true about grids?
A. They increase patient radiation
B. They should be used with smaller body parts
C. They should not be used with films of the pelvis
D. They work best if the lead strips are parallel
A. They increase patient radiation
Generally speaking, adding 4 kVp to a radiographic technique with a single phase machine would be equivalent to what?
Increasing the mAs by 30%
What would produce a film with the most visable grainy?
A high kVp/low mAs film
What is the recommended optimal kV range for an A-P thoracic film?
75-85 kV
What is the primary factor for radiographic density?
mAs
Which radiographic technique would cause the most absorption of x-rays in a patient’s body?
A. 10 mAs with 140 kV
B. 20 mAs with 90 kV
C. 30 mAs with 60 kV
D. 40 mAs with 40 kV
D. 40 mAs with 40 kV
The more mAs, the more absorption!
Which of the following is the closest to what is recommended for spinal filming with a stationary grid?
A. 8:1 with 100 lines per inch
B. 10:1 with 100 lines per inch
C. 12:1 with 200 lines per inch
D. 16:1 with 200 lines per inch
B. 10:1 with 100 lines per inch
10:1 or 12:1 with 100 lines is the range
How much increase in mAs is needed to maintain the same density when reducing the x-ray field from 14”x17” to 8”x10”?
60%
You send your associate to take lumbar x-rays on a 330 pound retired male wrestler who has a stomach ache. He takes the films in the recumbent position for the best possible quality. After seeing the first film, he tells you it’s too light. Due to the man’s size and the fact that you can see the spinal structures, the best thing to do would be to?
Increase the mAs by 100% (double it)
You have just purchased a new high frequency x-ray machine to replace the old, single phase unit, but your installer didn’t give you a new technique chart. You still have the single phase chart and decide to use it with appropriate modifications. What should you do as a starting point to try to make it work for you?
Decrease the mAs by 1/2
What refers to an attenuation of part of the beam by the grid?
Grid cut-off
When using a stationary grid, what ratio is recommended for spinal filming?
10:1 or 12:1
The use of a grid has which main effect on the patient?
A. It increases x-ray exposure to the patient
B. It reduces patient motion
C. It reduces x-ray exposure to the patient
D. It more evenly disburses the patient’s soft tissue
A. It increases x-ray exposure to the patient
The preferred focused grid range for spinal radiography is?
40” to 72”
If a film has an overall darkened gray appearance, but visible structures, the probable cause of the problem would be?
Exposure of the film to scatter
When converting from a grid with a low ratio to a grid with a high ratio, what would be the best thing to do to maintain good film quality?
Increase the mAs
If a film has an overall light appearance but visible structures, the probable cause of the problem would be?
Too low of a kVp technique
What is the most common cause of a blurry image in practice?
Patient motion
Which choice below is the main reason why a “fixed kV” technique is preferred?
A. Contrast is consistent
B. There is less stress on the tube
C. The patient exposure is reduced
D. A faster exposure time can be used
A. Contrast is consistent
What is the recommended optimal kV range for a lateral thoracic film?
85-95
Which of the following exposure techniques would have the lowest contrast?
A. 200 mAs with 75 kV
B. 150 mAs with 65 kV
C. 100 mAs with 95 kV
D. 50 mAs with 110 kV
D. 50 mAs with 110 kV
Which is preferred for spinal filming?
A. Fixed kV technique
B. Variable kV technique
C. High kV technique
D. Low kV technique
A. Fixed kV technique
What is an advantage of a high kVp technique?
Lowered patient radiation dose
If you increased the mAs and reduced the kV from a given radiographic technique what would be the outcome?
It would have more contrast
What best describes what you should expect if you retake an AP lumbar film with a 15% decrease in the kV and leave the mAs constant?
The density of the film would be reduced by 1/2
Which of the following would you do if you were going to use the 30% rule?
A. Alter the mAs by 30%
B. Alter the kV by 30%
C. Alter the kV by 15% and the mAs by 15%
D. Alter the kV by 10% and the mAs by 5%
A. Alter the mAs by 30%
If you were re-x-raying an obese patient because your first film was too light, but you could see structures, which of the following would be the best thing to do in order to get the best quality radiograph?
A. Increase exposure time
B. Increase the kV
C. Increase the mAs
D. Increase the FFD
C. Increase the mAs
If a film was taken at 80 kV and 100 mA for 1/2 second and a second was taken at 80 kV and 50 mA for one second and a third was taken at 80 kV and 200 mA for 1/4 of a second, what would be the outcome?
They would all be the same
You take a film and it is too light. You want to retake it and double the density by using kVp. How would you do it?
Increase the kVp by 15%
Which effect would adding 100% more mAs to a radiographic technique have?
It would double the density of the film
Which body part would absorb the most x-rays in a patient?
Their vertebra
Exceeding the optimal kV range while maintaining good density will yield a film that has which of the following?
A. A long scale contrast
B. A short scale contrast
C. An image that is too dark
D. An image that is too light
A. A long scale contrast
Which of the following is most closely related to “differential absorption?”
A. Subject contrast
B. Film density
C. Remnant radiation
D. Scatter radiation
A. Subject density
You’re x-raying the lumbo-pelvic region on a friend who is a 72-year-old male. While you are looking at the images on the films, you notice Abdula’s structures have absorbed the most x-rays from your procedure. What structure would that be?
His mildly osteoporotic pelvis
Bone > Water > Fat > Air
You are taking thoracic films of a 62-year-old female. The AP measurement is 29 cm, so you are considering how to progress. What will be essential to use?
A high frequency unit
If you foolishly decided not to use a grid for an AP lumbar film and adjusted the radiographic technique to maintain a good density, what would be the outcome?
The film would be very gray (due to lots of scatter)
If you wanted to alter your contrast so that a radiograph had more gray tones, what would you have to increase?
kV
Determine which radiographic technique would yield a longest scale of contrast.
A. 85 kV with 30 mAs
B. 95 kV with 10 mAs
C. 70 kV with 40 mAs
D. 80 kV with 20 mAs
B. 95 kV with 10 mAs
Long scale = high kV, low mAs
To double the density of a film by using mAs, what would you do?
Increase the mAs by 100% (double it)
If you had a film that was over-exposed, but you could see the image, what would improve your film?
Decrease the mAs by 50%
How much of an increase in mAs is needed to maintain the same density when reducing the x-ray field from 14”x17” to 8”x10”?
60%
If you wanted to decrease the density of a film, what would be the best way to go about it?
Reduce the mA
Want to keep stable kV if possible!
What best describes the outcome of reducing the mAs by 1/2 and keeping the kV and the distance constant?
The film density would be decreased
What would produce the same film density as 200 mA for 1/2 second?
A. 300 mA for 1.5 sec
B. 250 mA for 3/4 sec
C. 150 mA for 2 sec
D. 100 mA for 1 sec
D. 100 mA for 1 sec
If you took a retake and reduced the kVp by 15% and increased the mAs by adding 30%, how would the second film compare to the first?
The second film would be lighter (due to inc grays)
The 15% rule applies to what?
kV
The 50% rule applies to what?
mAs
You take an A-P thoracic film with 70 kV and 50 mAs and it came out underexposed, but you could see all of the structures. What would you do?
Increase the kV by 15%
AP thoracic kV range is 75-85 dummy!
As a general rule, if you are going to x-ray an elderly patient, you should do what to your established radiographic technique?
Decrease it
If patient is huge, increase it!
What is undesirable with magnification distortion?
A. The object will be altered in shape
B. The borders of the object will be blurred
C. The borders of the object will be darker
D. The object will appear smaller
B. The borders of the object will be blurred
What effect does using a high kV technique have?
Produces more scatter
The rays that exit the patient and hit the film are called?
Remnant rays
When going from a grid to a non-grid technique on the same body part, having the same FFD, kVp and mAs would cause what to happen?
The film would be darker
due to scatter!
A film that is lighter on one side than the other most likely would indicate?
Grid cut-off
Your friend Matt says he wants to get a reciprocating grid. Aaron says he wants to get a stationary focused one. Brian then says he wants to get a parallel linear grid, since it’s cheaper. Who has chosen wisely and wants the recommended type of grid?
Aaron- stationary focused is da bomb doe
You have purchased old equipment, and your installer says that the grid is old and bent. He says he has a brand new cross-hatched grid, a grid with wood interspacing material, one with bamboo interspacing and one with aluminum between the lead strips. Which should you choose as your replacement?
Aluminum
The _____ is the main function of mAs.
Film density (kV is film contrast!)
Which radiographic technique routinely uses an air-gap technique?
Lateral cervical
What effect does scatter radiation have on a film?
It causes graying of the film
The term “optimal kV” refers to what?
The highest possible contrast with the lowest possible kVp
The use of the air-gap technique can usually be done without what?
A grid
What increases Compton’s radiation?
Higher kVp
What would result in an increase in the amount of x-rays passing through a patient without an interaction with the patient’s atoms?
Higher kV
In which direction do grid lines run?
In the long axis of the patient
What is the optimal kV range for an A-P lumbar film?
80-90
In the office, what is the most common cause of grid cut-off?
The tube being out of alignment
The height of the grid’s lead strips compare to the width between them is termed?
Grid ratio
Which of the following is true about a reciprocating grid?
A. It requires a 10:1 ratio B. It requires 103 lines per inch C. It is thicker than a stationary grid D. It requires a faster exposure time E. It is less expensive than a stationary grid
C. It is thicker than a stationary grid
Which grid is recommended for spinal radiography in the usual chiro office?
A focused grid
How many lines per inch are recommended for a stationary grid?
100-103
Diminished penetration at the periphery of a grid is termed?
Grid cut-off
If a film is said to be “burned out” what would it look like?
Too dark
Remnant radiation refers to what?
Primary and scattered rays that leave the patient and reach the grid
What would produce the least amount of grid lines?
A moving grid
Which of the following would increase patient exposure?
A. Using a high kV technique
B. Using a 10:1 stationary grid
C. Using a high speed screen
D. Using an air-gap technique
B. Using a 10:1 stationary grid
How much of an increase in mAs is required when going form a non-grid technique to using a technique with a 12:1 grid?
5x (8:1 is 4x!)
If you took a 14”x17” lateral lumbar film and saw that L5-S1 was too light, what would be the best thing to do?
Take an 8x10” spot lateral and increase the mAs by 60%
If you saw a blood vessel on end (axially) on a chest film, it would probably look like which of the four natural body densities?
Water
If you saw 2 structures each with paralleling tracks of calcification overlying the articular pillars diverging at the superior and closer at the inferior, what would you be looking at?
Part of the thyroid cartilage
If you took an A-P lumbar on a thin patient at 85 kV at 100 mA with the exposure time of 1/2 sec and the film was too light but all structures were visible, what should you do to improve it?
Double the mAs
You decide to set up your practice where your aunt lives. She is an elderly, overweight, retired exotic dancer who injured her back when she fell off the pole. You first take an A-P lumbar film using 90 kV with 100 mAs for 1 second at 40” SID. The film comes out very gray. What is the best way to retake it?
Use 200 mA and decrease the kV 15%
You are performing cervical x-rays on The Rock. You take the lateral at 65 kV and 10 mAs without a grid, and the film is too light but structures are visible. What would be the best thing to do for the retake?
Increase the kV 15% (normal range for LC is 75-85!)
