Rad Phys Exam 2 Flashcards
(213 cards)
Of the choices below, which is true about a reciprocating grid?
it requires a 10:1 ratio
it requires 103 lines per inch
it is thicker than a stationary grid
it requires a faster exposure time
it is less expensive than a stationary grid
it is thicker than a stationary grid
To double density of a film by using mAs, What would you do?
increase the mAs by 100%
When converting from a grid with a low ratio to a grid with a high ratio which of the following would be the best to do to maintain good film quality?
increase the mAs
Which of the following is recommended for spinal radiography in the usual chiropractic office?
a focus grid
which of the following effects does using a high kV technique have?
produces more scatter
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 which of the following?
exposure of the film to scatter
The term “optimal kV” refers to which of the following?
the lowest possible mAs with acceptable contrast on the film
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
Which choice below is the main reason why a “fixed kV technique is preferred?”
Contrast is consistent
Remnant radiation refers to which of the following?
Scattered rays that leave the patient and reach the grid and primary rays that leave the patient and reach the grid
Which of the following would produce the least amount of grid lines?
a moving grid
Exceeding the optimal kV range while maintaining good density will yield a film that has which of the following?
a long scale contrast
As a general rule, if you are going to x-ray an elderly patient you should do which of the following to your established radiographic technique?
decrease it
Which of the following would increase patient exposure?
- using a high kV technique
- using a 10:1 stationary grid
- using a high speed screen
- using an air gap technique
using a 10:1 stationary grid
If you took a lateral cervical x-ray with 66kV at 100 mAs for 1/10 of a second at 72” FFD and it was too light but you see the structures, which of the following would be the best solution for your retake?
increase the kV by 15% (optimal kV cervical spine 75-85 kV)
About how much increase in mAs is required when going from a non grid technique to suing a technique with a 12:1 grid?
5 times
If you took a 14x17” lateral lumbar and saw that the L5-S1 area was too light, which of the following would be the best thing to do?
take a spot 8x10” lateral, increase the mAs by 60% and increase the kV
If you saw a blood vessel on end (axially) on a chest film it would probably look like which of the four natural body (subject) 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 at what would you be looking?
part of the thyroid cartilage
If you took an A-P lumbar on a thin patient using 85kV at 100mA with the exposure time of 1/2 second and the film demonstrated all of the structures but was too light which should you do to get a better film?
increase the mAs by doubling it
Of the choices below which is true about a reciprocating grid?
- it requires a 10:1 ratio
- it requires 103 lines per inch
- it is thicker than a stationary grid
- it requires a faster exposure time
- it is less expensive than a stationary grid
it is thicker than a stationary grid