Computed Tomography- Test 1

Computed Tomography- Test 1
Tomos-A-AAnswerAGreekAwordAmeaning:Asection


InitiallyAknownAasA-AAnswerAComputerAAssistedATomography


EvolvedAtoA-AAnswerAComputerizedAAxialATomography


Currently,AComputedAtomographyAisAusedAsinceACTAimagesAareAavailableAin:A-
AAnswerAsagittal,Acoronal,AandAaxialAplanesA(horizontal)



Dr.AGodfreyAHoundsfieldA-AAnswerAinventedAtheAfirstAcomputedAtomography


1971ATheAEMIAMarkA1A-AAnswerA(CTAbrainAscannerAprototype)AwasAinstalledAatAAtkinson-
Morley'sAHospitalAunderAtheAdirectionAofAradiologist,ADr.AJamesAAmbrose.


1972A-
AAnswerAAAwomanAwithAaAsuspectedAbrainAlesionAwasAtheAfirstApatientAscanned.ATheAscan
nerAconfirmedAtheApresenceAofAtheAlesion.


AllanACormackA-
AAnswerAPhysicsAProfessorAatATuftsAUniversity,AdevelopedAtheAmathematicsAusedAtoAreconstr
uctACTAimagesA(algorithms)


HoundsfieldA&ACormackA-
AAnswerAsharedAtheANobelAPrizeAinAMedicineAinA1979AforAtheirAcontributionsAtoACT



Dr.ARobertALedleyA-
AAnswerAProfessorAofAradiology,Aphysiology,A&AbiophysicsAatAGeorgetownAUniversity,Adevel
opedAtheAfirstAwholeAbodyAscanner.


DataAAcquisitionsA-
AAnswerArefersAtoAtheAmethodAbyAwhichAaApatientAisAscannedAandAtheAdataAisAusedAforAi
mageAreconstruction

, TypeAofAscanningAdependsAonAthe:A-
AAnswerAbeamAgeometryA(shapeAofAtheAradiationAbeam)AwhichAisAbasedAonAtheAspecificACT
AmachineAandAcomponentsAthatAareAused.



3AtypesAofAacquisitionAgeometriesA-AAnswerA1.AparallelAbeam
2.AfanAbeamA
3.AspiralAbeam


2AelementsAinAaAbasicAschemeAforAdataAacquisitionAare:A-
AAnswerAbeamAgeometryA&Acomponents



BeamAGeometry:A-
AAnswerArefersAtoAtheAshape,Asize,AandAmotionAofAtheAbeamAandAitsApath.



Components:A-
AAnswerAreferAtoAtheAphysicalAdevicesAthatAshapeAorAdefineAtheAbeam,AmeasureAitsAtransm
issionAthroughAtheApatient,AandAconvertAtheAanalogAdataAintoAdigitalAdataAforAinputAintoAthe
Acomputer.



FirstAGenerationA-AAnswerA-translateAandArotateAmotionAtypeA(beamAgeometry-
Ashape,Asize,AmotionAofAbeam)


-utilizedAaAparallelA(pencilAthin)Ax-rayAbeamAwithA1AlinearAdetector


-
dataAacquisitionAprocess:A1AbeamAandA1AdetectorAfirstAtranslatesA(makesA1Asweep)AacrossAth
eApatientAtoAcollectAreadings.AAfterA1Atranslation,AtheAtubeA&AdetectorArotateA1AdegreeAandA
repeatAtheAprocessAuntilA180AtranslationsAhaveAbeenAachieved.A


-disadvantage:AexposureAtimeArequiredA5AminAforA1AsliceA(mm)


-HeadACTAcapabilityAonly


SecondAGenerationA-AAnswerA-translateAandArotateAmotionAtype