22 terms

# Radiology Chapter 4

Exposure Factors
###### PLAY
Caliper
a device used to measure the thickness of anatomic parts
Contrast
the measurable difference between two adjacent densities
Density
the degree of blackness on a radiograph
Exposure Time
the period of time during which x-rays are permitted to leave the x-ray tube
Inverse Square Law
the intensity of the radiation varies inversely as the square of the distance from the source
Kilovoltage
related to thousands of volts. Describes the electrical potential (differences) between the cathode and the anode; it is responsible for accelerating the electrons from the cathode to the anode and relates to the penetrating power the x-rays.
Kinetic energy
the energy related to motion
Milliamperage-seconds (mAs)
the number of x-rays produced over a given period. Calculated by multiplying the milliamperage by the time
Milliampere
one thousandth of an ampere. A measure of electron current to the filament, which has a direct relationship to the number of x-rays produced.
Sante's rule
a method of estimating kilovoltage in relation to area thickness (2x thickness) +40 = kVp
Source-image distance (SID)
formerly called focal-film distance (FFD) the distance between the source of x-rays and the image receptor or film
Thermionic emmission
the process of releasing electrons from their anatomic orbits by heat
ways to decrease the number of personnel in the radiology suite include
sedating patients
ways to increase penetrating power of x-rays include
increasing kVp
the milliamperage-seconds (mAs) for 1000 mA and 1/10 sec is
100 mAs
According to Sante's rule, if a cat's abdomen measures 12cm, kVp is
64
The source-image distance
must be considered each time the control panel is set
one percent of the energy produced at the anode is in the form of
x-rays
The temperature of the filament within the cathode is controlled by
mA setting
Which is a characteristic of x-rays
their intensity increases as SID decreases
The potential difference between the anode and cathode is measured in
kilovolts
A higher kVp setting allows for a ________ mAs and ______exposure time
lower, lower