Radiography Calculations Flashcards
what is the relation between kV and electrons?
the higher the kV, the faster the electrons will travel towards the anode
what happens to the wavelength and colour of the image with a high kV?
- short wavelength
- darker image
what happens to the wavelength and colour of the image with a low kV?
- lower wavelength
- paler image
what is the relation between mA and the colour of the image?
a high mA results in more x-rays and therefore a blacker image
what is the relation between time and the number of x-rays produced?
the longer the time, the more x-rays produced
what is a grid?
a flat plate which is placed between the patient and the cassette
what does a grid consist of?
a series of thin, lead strips alternating with strips of a material that allows x-rays to pass through
what is a parallel grid?
stationary grid with alternating vertical strips of lead and radiolucent material
what is a focused grid?
stationary grid with central alternating vertical strips and gradually sloping strips of lead and radiolucent material
what is a pseudo focused grid?
stationary grid with vertical slats that become shorter on the edges
what is a crossed grid?
stationary grid with vertical and horizontal strips of a radiolucent material
what is a pro and con of using a grid during x-rays?
pro - reduces scatter radiation
con - expensive to buy
if an x-ray was overexposed, what colour would it be?
black
if an x-ray was underexposed, what colour would it be?
white
what is density?
The degree of blackening of an x-ray
