Radt. 3000 principles of exposure

Attenuation

partial absorption of x- ray beam as it passes through body.

KVp kilovoltage peak

energy level in which electricity is being forced across x- ray tube; peak energy level.

AEC (Automatic Exposure Control)

allows radiographer to set kVp & system determines when adequate exposure has reached IR

Primary Radiation /Beam

refers to beam from focal spot to object being imaged (patient)

Artifact

any extraneous object or unwanted image that obscures info in radiograph.

Elongation

when object appears longer in image than it actually is.

Inherent Filtration

built into x- ray tube; consists of 3 parts- 1 .)

Focal Spot

refers to specific target area on target surface of x- ray tube.

Grids

absorb scatter before it reaches IR.

Brightness

measurement of the luminants of an area in a radiographic image displayed on a monitor.

Anoheel effect

difference in beam intensity along longitudinal axis of x- ray tube.

Noise

any undesirable info that interferes with subject of interest in radiographic image.

Added Filtration

added by technologist

MA (milia Ambridge)

measurement of flow rate of electrons through x- ray tube.

Spatial Resolution

sharpness of structural edges recorder in the image.

Contrast

visible difference between any 2 selected brightness levels within displayed radiographic image.

Magnification

difference between size of object in image vs the actual size of object.

Subject Contrast

magnitude of signal difference in remanent beam; as a result of different absorption characteristics of tissues & structures making up the part (difference in the part;

Exposure latitude

range of exposures which produces quality images at appropriate patient dose.

Filtration

purpose to absorb low energy x- ray photons before they reach patient.

Density Control

each increment in Density Control setting represents 25 % change in intensity.

Receptor exposure

amount of exposure striking the IR.

Dynamic Range

________- range of exposures that can be captured by a detector.

SID (Source to Image Distance)

Distance of CR from focal spot to IR.

Central Ray

________- center of x- ray beam & direction in which it travels.

*Spatial Resolution

sharpness of structural edges recorder in the image

*Receptor exposure

amount of exposure striking the IR

*Brightness

measurement of the luminants of an area in a radiographic image displayed on a monitor

*Contrast

visible difference between any 2 selected brightness levels within displayed radiographic image

*Gray Scale

refers to # of brightness levels or shades of gray

*Long Scale Contrast

slight differences between gray shades are present (low contrast); total # of gray shades is great

*Short Scale

major/considerable differences between gray shades present (high contrast); total # of gray shades is small

*Dynamic Range

range of exposures that can be captured by a detector

*Receptor Contrast

doesnt go over

*Exposure latitude

range of exposures which produces quality images at appropriate patient dose

*Subject Contrast

magnitude of signal difference in remanent beam; as a result of different absorption characteristics of tissues & structures making up the part (difference in the part;

****Short Scale

only when looking at bony anatomy

****Detector

IR

****ALARA

As Low As Reasonably Achievable

*Digital Radiography

general term that includes computed & direct radiography

*Clinical Radiography (CR)

when you have to poke IR in machine to scan IR

*Digital Radiography (DR)

Wireless IR

Noise

any undesirable info that interferes with subject of interest in radiographic image

Artifact

any extraneous object or unwanted image that obscures info in radiograph

Size Distortion

aka magnification

Magnification

difference between size of object in image vs the actual size of object

Shape Distortion

difference between shape of object in image vs actual shape of object

Elongation

when object appears longer in image than it actually is

Foreshortening

when object appears shorter in image than it actually is

*mA (milia Ambridge)

measurement of flow rate of electrons through x-ray tube

*time(s) (exposure time)

abbreviated in seconds (s); amount of time in seconds during exposure

*mAs (millie Amber seconds)

mA & time put together; total exposure

*kVp (kilovoltage peak)

energy level in which electricity is being forced across x-ray tube; peak energy level

*Focal Spot

refers to specific target area on target surface of x-ray tube

*AEC (Automatic Exposure Control)

allows radiographer to set kVp & system determines when adequate exposure has reached IR

-Density Control

each increment in density control setting represents 25% change in intensity

*APR (Anatomically Programmed Radiography)

preset technical factors

*4 things needed to produce X-Rays

1.) source of electrons 2.) focusing cup 3.) way to speed up electrons 4.) have a way to stop electrons abruptly

*SID (Source to Image Distance)

distance of CR from focal spot to IR

*Primary Radiation/Beam

refers to beam from focal spot to object being imaged (patient)

*Remnant Beam

sometimes called image forming radiation; where it exits patient down to IR

*attenuation

partial absorption of x-ray beam as it passes through body

*Added Filtration

added by technologist

*Filtration

purpose to absorb low energy x-ray photons before they reach patient

*Anoheel effect

difference in beam intensity along longitudinal axis of x-ray tube

*Central Ray

center of x-ray beam & direction in which it travels

*Grids

absorb scatter before it reaches IR