simple presentation abt CT scan

1. CT scan
(computed tomography)

2. What is CT scan
computed tomography
Computed:use of computer for result
Tomography:greek word tomos mean
“slice”,graphy mean”write”

3. • A computed tomography (CT ) scan allows doctors to see inside
your body for diagnosis . It uses a combination of X-rays and a
computer to create pictures of your organs, bones, and other
tissues.

4. CT equipment

5. How it’s work
• CTscansarecreatedusingaseriesofx-rays,whichareaformof
radiationontheelectromagneticspectrum.Thescanneremitsx-rays
towardsthepatientfromavarietyofangles–andthedetectorsinthe
scannermeasurethedifferencebetweenthex-raysthatareabsorbed
bythebody,andx-raysthataretransmittedthroughthebody.Thisis
calledattenuation.
• Theamountofattenuationisdeterminedbythedensityoftheimaged
tissue,andtheyareindividuallyassignedaHounsfieldUnitorCT
Number

6. • Highdensitytissue(suchasbone)absorbstheradiationtoagreater
degree,andareducedamountisdetectedbythescannerontheopposite
sideofthebody
• Lowdensitytissue(suchasthelungs),absorbstheradiationtoalesser
degree,andthereisagreatersignaldetectedbythescanner.
• ThosetissueswithhighHounsfieldValue(strongabsorption)showup
white,andthosewhichabsorbwithlowHounsfieldValue(weak
absorption)showupblack

8. What does a CT scan show?
• Certain types of cancer and benign
(noncancerous) tumors.
• Fractures (broken bones).
• Heart disease.
• Blood clots.
• Brain and spinal cord diseases or injuries.
• Internal bleeding

9. Broken knee
NormalKnee

10. Tumor in brine

11. Normal brine
hemorrhage

12. Broken in skull

13. calcification
Toxoplasma Infection

14. Normal lung
Covid -19
infection
Bacterial
pneumonia

16. Contrast material
• AspecialdyecalledcontrastmaterialisneededforsomeCTscanstohelp
highlighttheareasofyourbodybeingexamined.Thecontrastmaterial
blocksX-raysandappearswhiteonimages,whichcanhelpemphasizeblood
vessels,intestinesorotherstructures.Mostareiodine
• Injection:Thedrugsareinjecteddirectlyintoavein.Thisisdonetohelpyour
bloodvessels,urinarytract,liver,orgallbladderstandoutintheimage.
• Orally:Drinkingaliquidwiththecontrastmaterialcanenhancescansof
yourdigestivetract,thepathwayoffoodthroughyourbody.
• Enema:Ifyourintestinesarebeingscanned,thecontrastmaterialcanbe
insertedinyourrectum.

17. Lung with contrst
(occlusive pulmonary
embolism)

18. How you prepare
Depending on which part of your body is being scanned, you may be
asked to:
• Takeoffsomeorallofyourclothingandwearahospitalgown
• Removemetalobjects,suchasabelt,jewelry,denturesandeyeglasses,
whichmightinterferewithimageresults
• Refrainfromeatingordrinkingforafewhoursbeforeyourscanifit

19. If your CT scan uses dye or contrast:
Bloodtest:YoumayneedabloodtestbeforeyourscheduledCTscan.Theblood
testwillmakesurethehealthcareproviderchoosestherightdye.
Dietrestrictions:Youwillneedtowatchwhatyoueatanddrinkforthefourhours
beforeyourCTscan.Consumingonlyclearliquidshelpspreventnauseawhenyou
receivethecontrastdye.
Allergymedication:IfyouareallergictothecontrastagentusedforCT(which
containsiodine),youmayneedtotakeasteroidmedicationthenightbeforeand
morningofyourprocedurealongwithanantihistamine
Preparationsolution:Youshoulddrinktheoralcontrastsolution
Fordiabetespatientstopdrug“metformin”Contrastdyecanincreasethechances
ofmetformincausinglacticacidosisinpatientswithdecreased kidneyfunction

20. During the test
• Youlieonanarrow,motorizedtablethatslidesthroughtheopeningintoatunnel.
Strapsandpillowsmaybeusedtohelpyoustayinposition.Duringaheadscan,
thetablemaybefittedwithaspecialcradlethatholdsyourheadstill
• Whilethetablemovesyouintothescanner,detectorsandtheX-raytuberotate
aroundyou.Eachrotationyieldsseveralimagesofthinslicesofyourbody.You
mayhearbuzzingandwhirringnoises
• Atechnologistinaseparateroomcanseeandhearyou.Youwillbeableto
communicatewiththetechnologistviaintercom.Thetechnologistmayaskyouto
holdyourbreathatcertainpointstoavoidblurringtheimages.
• Whentheexamisover,thetablemovesbackoutofthescanner.

22. After the exam
• youcanreturntoyournormalroutine.Ifyouweregiven
contrastmaterial,youmayreceivespecialinstructions.In
somecases,youmaybeaskedtowaitforashorttime
beforeleavingtoensurethatyoufeelwellaftertheexam.
Afterthescan,you'lllikelybetoldtodrinklotsoffluidsto
helpyourkidneysremovethecontrastmaterialfromyour
body

23. How long does the test take?
• Typically, you should plan for an hour for a CT
scan. Most of that time is for preparation. The
scan itself takes between 10 and 30 minutes
or less

24. What are the risks associated with a CT
scan?
• safe, painless test is noninvasive and has very
little risk.
• exposure to radiation:
The low doses of radiation used in CT scans have not been shown to
cause long-term harm, although at much higher doses, there may be
a small increase in your potential risk of cancer.
CT scans have many benefits that outweigh any small potential risk.
Doctors use the lowest dose of radiation possible to obtain the needed
medical information
• allergic reactions to contrast dyes

25. CT scan if for pregnant?
• CT scans of the pelvis and abdomen can
subject the unborn baby to radiation, but it’s
not enough to cause actual harm. CT scans in
other parts of the body don’t put your baby at
any risk.

26. X rays or CT
• on X-rays, body structures appear to overlap, making
it difficult to see everything. The CT scan shows
spaces between organs for a clearer view.
• x-rays provide the radiographer with a two-
dimensional image, and require the patient to be
moved manually to image the same region from a
different angle. In contrast ,CT the three-dimensional
planes of the human body

27. X ray CT