Image production and evaluation
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Image Production and Evaluation. NOTE: QA AND QC ARE USED INTERCHANGABLY IN APPLETON AND LANGE. Intensifying screen (ref: pg 59 Mosby, 190 Bushong). Base Reflective layer Active Layer Protective layer. Intensifying.Screen: Detail and speed.

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Image production and evaluation

Image Production and Evaluation

NOTE: QA AND QC ARE USED INTERCHANGABLY IN APPLETON AND LANGE


Intensifying screen ref pg 59 mosby 190 bushong

Intensifying screen(ref: pg 59 Mosby, 190 Bushong)

  • Base

  • Reflective layer

  • Active Layer

  • Protective layer


Intensifying screen detail and speed

Intensifying.Screen: Detail and speed

  • Thicker the active layer: less detail and more speed

  • Larger the phospher:less detail and more speed

  • Formula: old screen

    new screen


Digital imaging

PSP

CRT

ADC

IP

CR

DR

FOV field of view or how much of the patient is included in the matrix

Matrix-rows and columns of pixels (512 x512)

Pixel size

As matrix increase, pixel size decreases

As FOV increases, pixel size increases

As pixel size increases, resolutions decreases

Digital Imaging


Target angle line focus principle pg 40 i n mosby

TARGET ANGLELINE FOCUS PRINCIPLEPG. 40 i-n, Mosby

  • Actual

  • Effective

  • Large angle

  • small angle

  • anode heel


Mammography

MAMMOGRAPHY

  • Use very low KVP 23-28

  • molybdenum targets

  • High MAS


Processing pg 62 mosby 180 bushong

PROCESSINGPG. 62 MOSBY,180 Bushong


Define

DEFINE

  • EXIT (REMNANT RADIATION)

  • LATENT IMAGE

  • MANIFEST IMAGE


Magnification for every 1 of oid increase sid must increase by 7 wallace pg 27 33

Magnification: FOR EVERY 1” OF OID INCREASE, SID MUST INCREASE BY 7”WALLACE PG 27-33

  • Mag. Factor - SID

    SOD

  • SOD ---- SID - OID

  • IMAGE SIZE -image = SID

    object SOD

  • % OF MAG- OID

    SOD X 100

  • #s 25,45 57,87,93


Density

DENSITY

  • OD or Logarithm of opacity

  • Ratio of amount of light incident on film to the amount of light transmitted thru film (Mosby, pg. 53)

  • Controlling factors

    • mAs

    • kVP

    • Distance

    • Film/screen

    • Grids

    • Collimation

    • Anatomy/pathology

    • Anode Heel

    • Filtration


Detail

Detail

  • Focal spot size

  • Screen speed

  • SID

  • OID

  • Motion artifact


Contrast

CONTRAST

  • KVP

  • GRID

  • FIELD SIZE

  • Filtration

  • Anatomy and pathology

  • HIGH, SHORT

  • LOW, LONG


Characteristic h d curve pg 58 mosby

CHARACTERISTIC/H&D CURVE PG 58 MOSBY

  • Exposure error latitude

  • Contrast latitude

  • speed of film

  • base/fog

  • processing


Differential absorption attenuation

DIFFERENTIAL ABSORPTION & ATTENUATION

  • Difference between x-rays absorbed through photoelectric effect and those not absorbed at all.


Quantum mottle

Quantum Mottle

  • Mottled appearance (looking through a mist)

  • low mas-increase QM

  • high speed film- increase QM


Grids

GRIDS

  • GRID RATIO: HEIGHT DIVIDED BY DISTANCE

  • AFFECT ON CONTRAST

  • MULTIPLYING FACTOR

  • GRID CUTOFF


Focal spot blur

FOCAL SPOT/ BLUR

  • Umbra/penumbra or focal spot blur

  • Small FS = less

  • Large FS = more

  • Increased SID = less

  • decreased SID = more

  • increased OID = more

  • decreased OID = less


Film construction pg 166 167 bushong cassette

FILM CONSTRUCTION (Pg. 166-167 Bushong)/Cassette

  • BASE

  • EMULSION


Interactions

CHARACTERISTIC

COMPTON

INFRARED

CLASSICAL,

THOMSON, COHERENT

PHOTOELECTRIC

BREMSTRAULING

PAIR PRODUCTION

PHOTO-DISINTEGRATION

INTERACTIONS


Technique and exposure

Technique and Exposure


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