Medical Imaging

Medical Imaging, X-Ray, CT Scan, MRI, PET Scan.

1. Compiled By: Prof. G.B.Rathod
Email: [email protected]
Medical Imaging

2. What is medical Imaging?
Medicalimagingisthe
techniqueandprocessof
creatingvisualrepresentations
oftheinteriorofabodyfor
clinicalanalysisandmedical
intervention,aswellasvisual
representationofthefunctionof
someorgansortissues
(physiology).
(a)TheresultsofaCTscanoftheheadareshownassuccessivetransversesections.(b)AnMRI
machinegeneratesamagneticfieldaroundapatient.(c)PETscansuseradiopharmaceuticalsto
createimagesofactivebloodflowandphysiologicactivityoftheorganororgansbeingtargeted.(d)
Ultrasoundtechnologyisusedtomonitorpregnanciesbecauseitistheleastinvasiveofimaging
techniquesandusesnoelectromagneticradiation.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

3. What is medical Imaging?
Medicalimagingisoften
perceivedtodesignatethe
setoftechniquesthat
noninvasivelyproduce
imagesoftheinternal
aspectofthebody.Inthis
restrictedsense,medical
imagingcanbeseenasthe
solution
ofmathematicalinverse
problems.
CT scanning(volume renderedin this case) confers aradiation doseto the developing fetus.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

4. Principle of Radiation
Generalprinciplesofradiationprotectionfromthe
hazardofionizingradiationaresummarizedasthreekey
words;justification,optimization,anddoselimit.Because
medicalexposureofradiationhasuniqueconsiderations,
diagnosticreferencelevelisgenerallyusedasareference
value,insteadofdoselimits.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

5. Components Of X-Ray System
MoststandardX-raysystemshavethree
maincomponentswhichareaX-raytube,ahighvoltage
powersupply,andacontrolunit.Workingtogether,
thesecomponentsarecommontoallstandardsystems.
YouTube Link for detail view animation : Click here
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Prof.G.B.Rathod, EC Dept.BVM-EC453

6. Components Of X-Ray System
TheX-raygenerator
providesthree
thingsthatare
requiredtoproduce
X-rays,andtheyare
asourceof
electrons,ameans
ofacceleration,and
atargetfor
interaction.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

7. X-Ray System
AnX-raymachineisanymachinethatinvolvesX-rays.It
mayconsistofanX-raygeneratorandanX-raydetector.
Examplesinclude:Machinesformedicalprojectional
radiography.Machinesforcomputedtomography.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

8. X-Ray System
Today's x-ray
machinesproduceastream
ofelectromagneticradiation
thatinteractswithananode
inanx-raytube.Thex-
raysmadebythisinteraction
arethendirectedtowardthe
partofthebodybeing
examined.Toreduce
radiationexposure,x-ray
machinesaimthex-raysat
onlythefocusarea.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

9. X-Ray System
Projectionalradiography,alsoknownasconventionalradiography,isa
formofradiographyandmedicalimagingthatproducestwo-dimensional
imagesbyx-rayradiation.Theimageacquisitionisgenerallyperformedby
radiographers,andtheimagesareoftenexaminedbyradiologists.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

10. X-Ray System
AnX-raymachineproducesacontrolled
beamofradiation,whichisusedtocreatean
imageoftheinsideofyourbody.Thisbeamis
directedattheareabeingexamined.After
passingthroughthebody,thebeamfallsona
pieceoffilmoraspecialplatewhereitcastsa
typeofshadow.Differenttissuesinthebody
blockorabsorbtheradiationdifferently.
Densetissue,suchasbone,blocksmostof
theradiationandappearswhiteonthefilm.
Softtissue,suchasmuscle,blocksless
radiationandappearsdarkeronthefilm.
Oftenmultipleimagesaretakenfrom
differentanglessoamorecompleteviewof
theareaisavailable.Theimagesobtained
duringX-rayexamsmaybeviewedonfilm
orputthroughaprocesscalled“digitizing”so
thattheycanbeviewedonacomputer
screen.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

11. Principle of the CT Scan
Theterm“computedtomography”,orCT,referstoacomputerizedx-rayimagingprocedure
inwhichanarrowbeamofx-raysisaimedatapatientandquicklyrotatedaroundthebody,
producingsignalsthatareprocessedbythemachine’scomputertogeneratecross-sectional
images—or“slices”—ofthebody.Theseslicesarecalledtomographicimagesandcontain
moredetailedinformationthanconventionalx-rays.Onceanumberofsuccessiveslicesare
collectedbythemachine’scomputer,theycanbedigitally“stacked”togethertoformathree-
dimensionalimageofthepatientthatallowsforeasieridentificationandlocationofbasic
structuresaswellaspossibletumorsorabnormalities.
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Prof.G.B.Rathod, EC Dept.BVM-EC453

12. Principle of the CT Scan
CTisbasedonthefundamentalprinciplethatthedensityofthe
tissuepassedbythex-raybeamcanbemeasuredfromthecalculation
oftheattenuationcoefficient....Unlikex-rayradiography,the
detectorsoftheCTscannerdonotproduceanimage.
Lets see how X-Ray and CT Scan is helping in the Health Care sector. 12
Prof.G.B.Rathod, EC Dept.BVM-EC453

13. PET Scan
Apositronemissiontomography(PET)scanisanimagingtestthat
allowsyourdoctortocheckfordiseasesinyourbody.
Thescanusesaspecialdyecontainingradioactivetracers.These
tracersareeitherswallowed,inhaled,orinjectedintoaveinin
yourarmdependingonwhatpartofthebodyisbeingexamined.
Certainorgansandtissuesthenabsorbthetracer.
WhendetectedbyaPETscanner,thetracershelpyourdoctorto
seehowwellyourorgansandtissuesareworking.
LetsSeeHowPETScanisdone?
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Prof.G.B.Rathod, EC Dept.BVM-EC453

14. PET Scan
Apositronemissiontomography(PET)scanisanimagingtestthathelps
revealhowyourtissuesandorgansarefunctioning.APETscanusesa
radioactivedrug(tracer)toshowthisactivity.Thisscancansometimes
detectdiseasebeforeitshowsuponotherimagingtests
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Prof.G.B.Rathod, EC Dept.BVM-EC453

15. MRI-Magnetic Resonance Imaging
Magneticresonanceimaging(MRI)isamedicalimaging
techniqueusedinradiologytoformpicturesoftheanatomyandthe
physiologicalprocessesofthebody.MRIscannersusestrong
magneticfields,magneticfieldgradients,andradiowavesto
generateimagesoftheorgansinthebody
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Prof.G.B.Rathod, EC Dept.BVM-EC453

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Prof.G.B.Rathod, EC Dept.BVM-EC453

17. MRI-Magnetic Resonance Imaging
An MRI scanner is a large tube that contains
powerful magnets. You lie inside the tube during
the scan.
An MRI scan can be used toexamine almost any
part of the body, including the:
Brain and spinal cord
Bones and joints, breasts
Heart and blood vessels
Internal organs, such as the liver, womb or
prostate gland
The results of an MRI scan can be used to help
diagnose conditions, plan treatments and assess
how effective previous treatment has been.
Video to understand basic history about MRI : Click here
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Prof.G.B.Rathod, EC Dept.BVM-EC453

18. Thank You
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Prof.G.B.Rathod, EC Dept.BVM-EC453
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