General Radiology 07/02/2014

Arany-Toth Attila

PrinciplesPrinciples of of VeterinaryVeterinaryRadiologyRadiology

PrinciplesPrinciples of of VeterinaryVeterinaryRadiologyRadiology

Attila ARANYAttila ARANY --TÓTHTÓTHAttila ARANYAttila ARANY --TÓTHTÓTH

websitewebsite: : www.kisallatsebeszet.huwww.kisallatsebeszet.huwebsitewebsite: : www.kisallatsebeszet.huwww.kisallatsebeszet.hu

US: US: surgerysurgeryPW: PW: studentstudentUS: US: surgerysurgeryPW: PW: studentstudent 3

RadiologyRadiology:: thethe diagnosticdiagnostic and and therapeuticaltherapeuticaluseuse of of ionisingionising radiationradiation inin thethe medicinemedicine

>>>>radiologistradiologist

RadiographRadiograph:: thethe photographicphotographic ((staticstatic) image) image

RadiographyRadiography:: toto produceproduce and and interpretinterpret thetheradiographradiograph

FluoroscopyFluoroscopy:: toto produceproduce and and interpretinterpretdinamicdinamic radiographicradiographic image image

RadiologyRadiology:: thethe diagnosticdiagnostic and and therapeuticaltherapeuticaluseuse of of ionisingionising radiationradiation inin thethe medicinemedicine

>>>>radiologistradiologist

RadiographRadiograph:: thethe photographicphotographic ((staticstatic) image) image

RadiographyRadiography:: toto produceproduce and and interpretinterpret thetheradiographradiograph

FluoroscopyFluoroscopy:: toto produceproduce and and interpretinterpretdinamicdinamic radiographicradiographic image image

Definition

Wilhelm KonradWilhelm Konrad RöntgenRöntgen 1895 1895

cathode ray tube fluorescent plate

General Radiology 07/02/2014

Arany-Toth Attila

cathode ray tube fluorescent plate cathode ray tube fluorescent plate

cathode ray tube photopaper

••1895 1895 discoverydiscovery of of thethe xx--rayray

••1896 1896 thousandsthousands of of xx--rayray booksbooks

••1901 Nobel 1901 Nobel PrizePrize

••1895 1895 discoverydiscovery of of thethe xx--rayray

••1896 1896 thousandsthousands of of xx--rayray booksbooks

••1901 Nobel 1901 Nobel PrizePrize

I. What is x-ray?I. What is x-ray?

General Radiology 07/02/2014

Arany-Toth Attila

visible lightvisible light

photonphoton

1. wavelenght (l)2. frequency (γ)1. wavelenght (l)2. frequency (γ)

γ * l = cγ * l = c1020 1018 1016 1014 1012 1010 108 106 104

gamma

x-rays

UV

visible

light

infrared

micro-

waves

U

S

W

radioradio

longwaves

10-12 m 10-9 m 10-6 m 10-2 m 1m 103 m

frequency

wavelenght

1022

The spectrum of the electromagnetic radiationThe spectrum of the electromagnetic radiation

E

II. Production of x-raysII. Production of x-rayscathode

cloud of electrons

mA

kV

s

anode

99% heat,light

1% X-ray

The Anatomy of the XThe Anatomy of the X--ray Machineray MachineThe Anatomy of the XThe Anatomy of the X--ray Machineray Machine

control panel image receptor

x-ray tubegenerator

collimator

FluoroscopyFluoroscopyFluoroscopyFluoroscopy

General Radiology 07/02/2014

Arany-Toth Attila

Digital Digital radiographyradiographyDigital Digital radiographyradiography

(CR- computed radiography)

Indirect digital radiography

reader

cassette

PSP plate

(DR- digital radiography)

Direct digital radiography

flat panel

III. The characteristics of xIII. The characteristics of x--rayrayIII. The characteristics of xIII. The characteristics of x--rayray

1. invisible1. invisible

2. travels 2. travels

-- at the speed of light, at the speed of light,

-- in a straight linein a straight line

-- from given focal spotfrom given focal spot

-- to every direction of the space to every direction of the space

3. a magnetic field cannot deflect its direction3. a magnetic field cannot deflect its direction

4. can penetrate the matters, while its intensity 4. can penetrate the matters, while its intensity decreases and will be scattereddecreases and will be scattered

1. invisible1. invisible

2. travels 2. travels

-- at the speed of light, at the speed of light,

-- in a straight linein a straight line

-- from given focal spotfrom given focal spot

-- to every direction of the space to every direction of the space

3. a magnetic field cannot deflect its direction3. a magnetic field cannot deflect its direction

4. can penetrate the matters, while its intensity 4. can penetrate the matters, while its intensity decreases and will be scattereddecreases and will be scattered

IV. The effects of xIV. The effects of x--ray ray

(interaction with the matter)(interaction with the matter)

IV. The effects of xIV. The effects of x--ray ray

(interaction with the matter)(interaction with the matter)

General Radiology 07/02/2014

Arany-Toth Attila

The effects of xThe effects of x--rayrayThe effects of xThe effects of x--rayray

x-ray beamx-ray beam

bodybody

absorption = interactionabsorption = interaction

xx--ray beam + ray beam + material material = = interactioninteractionxx--ray beam + ray beam + material material = = interactioninteraction

biologicalbiological tissuetissue = = tissuetissue damagedamage

photoemulsionphotoemulsion == photochemicalphotochemical changechange

((e.ge.g radiographyradiography))

phosphourphosphour = = fluorescentfluorescent effecteffectcompoundscompounds ((e.ge.g. . intensifyingintensifying screenscreen,,

fluoroscopyfluoroscopy))

biologicalbiological tissuetissue = = tissuetissue damagedamage

photoemulsionphotoemulsion == photochemicalphotochemical changechange

((e.ge.g radiographyradiography))

phosphourphosphour = = fluorescentfluorescent effecteffectcompoundscompounds ((e.ge.g. . intensifyingintensifying screenscreen,,

fluoroscopyfluoroscopy))

The The effectseffects of of xx--rayray

The radiographic imageThe radiographic imageThe radiographic imageThe radiographic image

x-ray

x-ray

X-rayX-ray

General Radiology 07/02/2014

Arany-Toth Attila

The degree of the absorption depends on:

- thickness

- physical density

- atomic number

of the object.

The degree of the absorption depends on:

- thickness

- physical density

- atomic number

of the object.

Differential absorption→contrast

(different shades of grey)

Differential absorption→contrast

(different shades of grey)Human eye:

5% difference in density

(20-25 shades of gray)

Human eye:

5% difference in density

(20-25 shades of gray)

RadiographicRadiographic

opacities:opacities:

RadiographicRadiographic

opacities:opacities:

METAL/STONEMETAL/STONE

BONEBONEBONEBONE

FLUID/

SOFT TISSUE

FLUID/

SOFT TISSUE

FATFATFATFAT

GASGAS

The radiograph is The radiograph is a a negative photographic negative photographic image:image:

exposed areas: blackexposed areas: black

RADIOLUCENTRADIOLUCENT

unexposed areas: whiteunexposed areas: white

RADIOPAQUERADIOPAQUE

The radiograph is The radiograph is a a negative photographic negative photographic image:image:

exposed areas: blackexposed areas: black

RADIOLUCENTRADIOLUCENT

unexposed areas: whiteunexposed areas: white

RADIOPAQUERADIOPAQUE

Radiograph is a two dimensional Radiograph is a two dimensional image of a threeimage of a three--dimensional objectdimensional objectRadiograph is a two dimensional Radiograph is a two dimensional

image of a threeimage of a three--dimensional objectdimensional object

General Radiology 07/02/2014

Arany-Toth Attila

A radiographic image is alwaysA radiographic image is alwaysA radiographic image is alwaysA radiographic image is always

1.1. distorteddistorted

2.2. enlargedenlarged

3.3. unsharpunsharp

1.1. distorteddistorted

2.2. enlargedenlarged

3.3. unsharpunsharp

1. Distorsion1. Distorsion1. Distorsion1. Distorsion

2. Enlargment2. Enlargment2. Enlargment2. Enlargment

Film -object distance Film -focus distance

3. Image detail3. Image detail

1. Geometrical1. Geometrical

-- focal spot sizefocal spot size

-- focusfocus--film distancefilm distance

-- objectobject--film distancefilm distance

2. Motion (respiratory, voluntary etc.)2. Motion (respiratory, voluntary etc.)

3. Film speed, screen, grid3. Film speed, screen, grid

1. Geometrical1. Geometrical

-- focal spot sizefocal spot size

-- focusfocus--film distancefilm distance

-- objectobject--film distancefilm distance

2. Motion (respiratory, voluntary etc.)2. Motion (respiratory, voluntary etc.)

3. Film speed, screen, grid3. Film speed, screen, grid

SummationSummation

cassettecassette

filmfilmintensifying screenintensifying screen

intensifying screenintensifying screenspongespongespongesponge

gridgridgridgrid

TThe he aanatomynatomy of the of the

conventional conventional ffilmilm--ccassetteassette

TThe he aanatomynatomy of the of the

conventional conventional ffilmilm--ccassetteassette

General Radiology 07/02/2014

Arany-Toth Attila

penetratepenetratepenetratepenetrate

absorbedabsorbedabsorbedabsorbed

scatteredscattered

The xThe x--ray can (be)ray can (be)The xThe x--ray can (be)ray can (be)Scattered (secondary) radiationScattered (secondary) radiationScattered (secondary) radiationScattered (secondary) radiation••SecondarySecondarySecondarySecondarySecondarySecondarySecondarySecondary beambeambeambeambeambeambeambeam ::::::::-------- changedchangedchangedchangedchangedchangedchangedchanged directiondirectiondirectiondirectiondirectiondirectiondirectiondirection

-------- decreaseddecreaseddecreaseddecreaseddecreaseddecreaseddecreaseddecreased intensityintensityintensityintensityintensityintensityintensityintensity

••DoesDoesDoesDoesDoesDoesDoesDoes notnotnotnotnotnotnotnot taketaketaketaketaketaketaketake part part part part part part part part inininininininin image image image image image image image image formationformationformationformationformationformationformationformation

••ProducesProducesProducesProducesProducesProducesProducesProduces „fog” „fog” „fog” „fog” „fog” „fog” „fog” „fog” onononononononon filmfilmfilmfilmfilmfilmfilmfilm

••IncreasesIncreasesIncreasesIncreasesIncreasesIncreasesIncreasesIncreases thethethethethethethethe radiationradiationradiationradiationradiationradiationradiationradiation riskriskriskriskriskriskriskrisk forforforforforforforfor thethethethethethethethepersonnelpersonnelpersonnelpersonnelpersonnelpersonnelpersonnelpersonnel

••SecondarySecondarySecondarySecondarySecondarySecondarySecondarySecondary beambeambeambeambeambeambeambeam ::::::::-------- changedchangedchangedchangedchangedchangedchangedchanged directiondirectiondirectiondirectiondirectiondirectiondirectiondirection

-------- decreaseddecreaseddecreaseddecreaseddecreaseddecreaseddecreaseddecreased intensityintensityintensityintensityintensityintensityintensityintensity

••DoesDoesDoesDoesDoesDoesDoesDoes notnotnotnotnotnotnotnot taketaketaketaketaketaketaketake part part part part part part part part inininininininin image image image image image image image image formationformationformationformationformationformationformationformation

••ProducesProducesProducesProducesProducesProducesProducesProduces „fog” „fog” „fog” „fog” „fog” „fog” „fog” „fog” onononononononon filmfilmfilmfilmfilmfilmfilmfilm

••IncreasesIncreasesIncreasesIncreasesIncreasesIncreasesIncreasesIncreases thethethethethethethethe radiationradiationradiationradiationradiationradiationradiationradiation riskriskriskriskriskriskriskrisk forforforforforforforfor thethethethethethethethepersonnelpersonnelpersonnelpersonnelpersonnelpersonnelpersonnelpersonnel

GridGrid(Lysholm )(Lysholm )GridGrid(Lysholm )(Lysholm )

GridGrid((LysholmLysholm ))GridGrid((LysholmLysholm ))

•• objects more than 10 cm objects more than 10 cm

•• higher higher kV/kV/mAsmAs valuesvalues areare requiredrequired!!

GridGridGridGrid

parallelparallelparallelparallel focused focused focused focused

GridGridGridGrid

General Radiology 07/02/2014

Arany-Toth Attila

pseudofocused pseudofocused pseudofocused pseudofocused

GridGridGridGrid

•• ConvertsConverts thethe xx--rayray toto visiblevisible lightlight

• Reduces the amount of x-ray

IntensifyingIntensifying screenscreenIntensifyingIntensifying screenscreen

Radiographic film is much more

sensitive to light then to x-ray

Intensifying screen

x -r ay beam

scr een

f i lm

x -r ay beam

scr een

f i lm

Intensifying screenIntensifying screen

Cristal Cristal sizesize

SpeedSpeed Image Image sharpnesssharpness

FactorFactor XX--ray ray neededneeded

slowslow

mediummedium

fastfast

2525

12001200

IntensifyingIntensifying screenscreen

•• CaWoCaWo screensscreens:: blueblue lightlight

•• fromfrom 19801980-- rarerare earthearth screenscreen ::

–– blueblue oror greengreen

–– more more efficientefficient intensifyingintensifying

•• CaWoCaWo screensscreens:: blueblue lightlight

•• fromfrom 19801980-- rarerare earthearth screenscreen ::

–– blueblue oror greengreen

–– more more efficientefficient intensifyingintensifying

Film ProcessingFilm ProcessingFilm ProcessingFilm Processing

General Radiology 07/02/2014

Arany-Toth Attila

Film ProcessingFilm ProcessingFilm ProcessingFilm Processing

FilmFilm Latent ImageLatent Image Visible ImageVisible ImageFilmFilm Latent ImageLatent Image Visible ImageVisible Image

EXPOSUREEXPOSURE PROCESSINGPROCESSING

X-ray,

light

AgBr exposed Agphysical changephysical change chemical changechemical change

metalic Agmetalic Ag

DEVELOPINGDEVELOPING FIXATIONFIXATIONFIXATIONFIXATIONEXPOSIT IONEXPOSIT IONEXPOSIT IONEXPOSIT ION

•• The The unchangedunchanged AgBrAgBr is is dissolvabledissolvable ; here ; here thethe film film becomesbecomestransparenttransparent

•• The The unchangedunchanged AgBrAgBr is is dissolvabledissolvable ; here ; here thethe film film becomesbecomestransparenttransparent

Steps of film processing:

1. Developing

(2. Rinsing or stop bath)

3. Fixing

4. Washing

5. Drying

Steps of film processing:

1. Developing

(2. Rinsing or stop bath)

3. Fixing

4. Washing

5. Drying