Radiographic Positioning & Related Anatomy

Front 1

4 Primary Image Quality Factors

Back 1

*Density
*Contrast
*Resolution
*Distortion

Front 2

Density

Back 2

is the amount of blackness on the processed film image.

Front 3

What is the primary controlling factor of film density

Back 3

mAs.
Other factors influence density on film image include kV, part thickness, chemical development time/temperature, grid ratio & fil-screen speed.

Front 4

Anode Heel Effect

Back 4

the intensity of the radiation emitted from the cathode end of the x-ray tube is greater than that at the anode end.

Front 5

Radiographic Contrast

Back 5

-the difference in density on adjacent areas of a radiographic image.
-the greated this difference, the higher the contrast; the less the density differences, the lower the contrast.

Front 6

Contrast

Back 6

Different shades of gray.
Long-scale or short-scale contrast

Front 7

What is the secondary controlling factor for contrast?

Back 7

kV
*general rule of thumb - states that a 15% increase in kV will increase film density, similar to doubling mAs.

Front 8

Resolution

Back 8

recorded sharpness of structures on the image. AKA "detail" recorded detail, image sharpness or definition.

Front 9

Geometric Factors tath control of influence resolution.

Back 9

*Focal Spot Size
*SID
*OID (Object Image recptor Distance)

Front 10

The greatest deterrent to image sharpness is?

Back 10

Motion

Front 11

Distortion

Back 11

misrepresentation of object size or shape.

Front 12

Four primary controlling factors of distorition are:

Back 12

1. SID (Source image receptor distance)
2. OID (Object image receptor distance)
3. Object image receptor alignment
4. Central ray alighment/centering

Front 13

SID (Source Image receptor Distance)

Back 13

at greater SID, less magnification occurs than at a shorter SID.

Front 14

OID (Object Image receptor Distance)

Back 14

the closer the object being radiographed is to the image receptor, the less the magnification and shape distortion and the better the detail or resolution.

Front 15

Object IR (Image Receptor) Alignment

Back 15

alignment or plane of the object being radiographed in relation to the plane of the image receptor.

Front 16

Central Ray Alignment

Back 16

least possible distortion occurs at the centeral ray. Must be align properly

Front 17

Digital Images

Back 17

a numeric representation of the x-ray intensities taht are trasmitted through the patient. Viewed on computer monitor and are referred to as a soft-copy images.

Front 18

Algorithms

Back 18

systematic application of highly complex mathematical formulas

Front 19

Milliamperage (mA)

Back 19

controls the number of x-rays produced

Front 20

mAs

Back 20

controls the number of x-rays times the duration to the exposure.

Front 21

Kilovoltage (kV)

Back 21

controls the penetrating power of the x-rays with all radiographic imaging digital or film-screen systems

Front 22

Wide Latitude

Back 22

wide range of acceptance of exposure factors to produce an acceptable image.

Front 23

The factors used to evaluate digital image quality include:

Back 23

1. Brightness 2. Contrast
3.Resolution 4. Exposureindex
5.Exposure index 6. Noise

Front 24

Exposure Index (Degital Imaging)

Back 24

a numeric value that is representative of the exposure the image receptor received.

Front 25

Noise

Back 25

random disturbance that obscures or reduces clarity.

Front 26

Scatter Radiation

Back 26

is a potential source of noice that can be controlled by the use of grids and correct collimation.

Front 27

Post-processing

Back 27

changing or enhancing the electronic image in order to improved its diagnostic quality.

Front 28

Post-processing options

Back 28

Windowing, smoothing, magnification, edge enhancement, subtraction, image reversal, annotation.

Front 29

4 Types of Digital Imaging Technologies in use today?

Back 29

1. Computed Tomography (CT)
2. Digital Fluoroscopy (DF)
3. Computed Radiography (CR)
4. Direct Digital Radiography (DR)

Front 30

Picture Archiving & Communication Systems (PACS)

Back 30

P-Picture - digital images
A-Archiving - "electronic" storage of images
C- Communication: routing(retrieval/sending) and displaying of the images.
S- System -specialized computer network that manages the complete system.

Front 31

Alara

Back 31

the principle that radiation exposure should be kept as low as reasonably achievable.

Front 32

Attenuation

Back 32

a reduction in intensity of the x-ray beam due to absorption and scattering.

Front 33

Units of Radiation Dose

Back 33

Rad and Rem
Rad - patient dose
Rem - radiation protection

Front 34

Roentgen (R)

Back 34

radiation exposure in air measured by the amount of ionization in a given unit of air

Front 35

Annual dose limit

Back 35

the dose limiting recommendation for occupationally exposed workers is 5 rem (50 mSv) of whole-body effective dose(each year)

Front 36

Cumulative dose limit

Back 36

comulative lifetime ED limit fo an occupationally exposed workers is 1 rem (10mSv) times the years of age.
ex. 50 yr tech dose 50 rem(500 mSV).

Front 37

Alara Principles

Back 37

1. Always wear a film badge or monitoring device 2. Restrint devices 3. practice used of close collimation, filtrtion of primary beam, optimum kV techniques, high speed screens and film & min. repeat exams 4. 3-part cardinal rule - time,distance, shielding

Front 38

Skin Entrance Exposure

Back 38

where radiation first strikes the body.