Nuclear MedicineNuclear Medicine

Spring 2009Spring 2009

FINALFINAL

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NM TeamNM Team

Nuclear medicine MDNuclear medicine MD

PhysicistPhysicist

PharmacistPharmacist

TechnologistTechnologist

PatientPatient

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Principles of NMPrinciples of NM Uses radiopharmaceuticals Uses radiopharmaceuticals

for diagnosis, therapy and for diagnosis, therapy and medical researchmedical research

Small amounts of radioactive Small amounts of radioactive material usedmaterial used Sometimes no more than that Sometimes no more than that

received in CT or fluoroscopyreceived in CT or fluoroscopy

Studies physiologyStudies physiology Rather than structural Rather than structural

appearanceappearance

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TracersTracers Radioactive material that can be:Radioactive material that can be:

Injected, ingested or inhaledInjected, ingested or inhaled

Different tracers for different body partsDifferent tracers for different body parts organ-, tissue-, or even cell-specific organ-, tissue-, or even cell-specific

They produce gamma-ray emissions from They produce gamma-ray emissions from within organ being studiedwithin organ being studied

Gamma or scintillation camera transforms Gamma or scintillation camera transforms emissions into images emissions into images Provides information about functionProvides information about function

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Modality ComparisonsModality Comparisons

PET and SPECT for physiology PET and SPECT for physiology

X-ray measures structure, size and position of X-ray measures structure, size and position of human anatomyhuman anatomy

CT creates cross sectional images of anatomyCT creates cross sectional images of anatomy

What do all of these modalities have in What do all of these modalities have in common?common?

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Atom Components & Atom Components & IsotopesIsotopes

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Physical Principles of NMPhysical Principles of NM RadioactivityRadioactivity

Radiation of energy Radiation of energy from the nucleus of from the nucleus of atomatom

Can be in the form Can be in the form of alpha, beta of alpha, beta particles or gamma particles or gamma rays from the rays from the nucleusnucleus

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Basic Nuclear PhysicsBasic Nuclear Physics

NuclideNuclide Atom with a particular arrangement of protons and Atom with a particular arrangement of protons and

neutrons in the nucleusneutrons in the nucleus

RadionuclideRadionuclide Unstable nucleus that transmutes by way of Unstable nucleus that transmutes by way of

nuclear decay (return to ground state)nuclear decay (return to ground state)

Decay Decay Is the atoms attempt to regain stabilityIs the atoms attempt to regain stability By emission of alpha, beta and gamma radiationBy emission of alpha, beta and gamma radiation Different for each type of radionuclide Different for each type of radionuclide

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Half LifeHalf Life Physical time it takes Physical time it takes

for a quantity of for a quantity of radionuclide to radionuclide to decrease to ½ its decrease to ½ its original activityoriginal activity

Radionuclides half life Radionuclides half life can range from can range from milliseconds to yearsmilliseconds to years NM radionucldies range NM radionucldies range

from hours to daysfrom hours to days

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Nuclear PharmacyNuclear Pharmacy

RadiopharmaceuticalRadiopharmaceutical RadionuclideRadionuclide PharmaceuticalPharmaceutical

Technetium -99 Technetium -99 Short ½ life of 6.04 hoursShort ½ life of 6.04 hours Low energy gamma photon Low energy gamma photon

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Radiation SafetyRadiation Safety

Radiopharmaceuticals Radiopharmaceuticals must be sterilemust be sterile

Prep area must have Prep area must have isolated ventilationisolated ventilation

Protective measures Protective measures when administering or when administering or handling handling

Spills must be cleaned Spills must be cleaned immediatelyimmediately

Dosimetry devicesDosimetry devices Hands and badgesHands and badges

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Modern Day Gamma Modern Day Gamma CameraCamera

Scintillate means: to emit lightScintillate means: to emit light

Ionizing radiation causes certain materials to glowIonizing radiation causes certain materials to glow

Scintillation detectorScintillation detector Detects radiation by observing the emission of light Detects radiation by observing the emission of light

photons emitted by the materialsphotons emitted by the materials

PMT detect and convert light photons emitted PMT detect and convert light photons emitted from the crystal into and electronic signal that from the crystal into and electronic signal that amplifies the original photon signalamplifies the original photon signal

It is then sent to be viewedIt is then sent to be viewed

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DetectorsDetectors

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CollimatorsCollimators

Keep scattered rays from entering the Keep scattered rays from entering the scintillation crystalscintillation crystal Absorbs scattered gamma raysAbsorbs scattered gamma rays

Resolution and sensitivityResolution and sensitivity Physical characteristicsPhysical characteristics

Made of material with high atomic numberMade of material with high atomic number LeadLead

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CrystalsCrystals

Sodium iodide Thallium Sodium iodide Thallium Thick layer of crystalsThick layer of crystals

High energiesHigh energies Decreased resolutionDecreased resolution

Thin layer of crystalsThin layer of crystals Lower energiesLower energies Increased resolutionIncreased resolution

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PhotomultiplierPhotomultiplierTubesTubes Attached to the back Attached to the back

of the crystalsof the crystals

Detect and convert Detect and convert light photons into and light photons into and electronic signal that electronic signal that amplifies the original amplifies the original photon signalphoton signal About 80-100 in a About 80-100 in a

gamma cameragamma camera

Light pipeLight pipe Like a focusing deviceLike a focusing device

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Put it all TogetherPut it all Together

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ComputerComputer

Acquires and processes data Acquires and processes data received from camerareceived from camera In a time frameIn a time frame

Post-processingPost-processing Adjust contrast and densityAdjust contrast and density

RecordsRecords DosageDosage Quality controlQuality control

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Types of Camera SystemsTypes of Camera Systems

Single detectorSingle detector

Dual head Dual head

Triple headTriple head

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Single Head DetectorSingle Head Detector

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Dual Head DetectorDual Head Detector

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Triple Head DetectorTriple Head Detector

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Imaging MethodsImaging Methods

StaticStatic Whole- BodyWhole- Body DynamicDynamic SPECTSPECT Co-registrationCo-registration PETPET

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StaticStatic

Single image of a particular structureSingle image of a particular structure Demonstrates radiopharmaceutical distributionDemonstrates radiopharmaceutical distribution Ex: lung scans, spot bone scans images, Ex: lung scans, spot bone scans images,

thyroid imagesthyroid images Obtained in various orientations, anterior, Obtained in various orientations, anterior,

posterior, and obliqueposterior, and oblique Low activity levelsLow activity levels

Generally 30 seconds to five minutesGenerally 30 seconds to five minutes

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Whole Body Whole Body

Entire body or a large section of bodyEntire body or a large section of body

Primarily used forPrimarily used for Bone scansBone scans Tumor scansTumor scans Abscess imagingAbscess imaging Clinical and research applicationsClinical and research applications

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Dynamic Dynamic

Timed record of distribution of Timed record of distribution of radiopharmaceuticalradiopharmaceutical

Commonly used forCommonly used for Cardiac studiesCardiac studies Hepatobiliary studies Hepatobiliary studies Gastric emptying studiesGastric emptying studies

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Dynamic RenogramDynamic Renogram

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Dynamic VenogramDynamic Venogram

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SPECTSPECT

Images similar to CT & MRIImages similar to CT & MRI thin slices through a particular organthin slices through a particular organ

360 degree rotatator heads allows for:360 degree rotatator heads allows for: Coronal, planar and 3D imagingCoronal, planar and 3D imaging

Ex: cardiac perfusion, brain, liver and Ex: cardiac perfusion, brain, liver and bone studiesbone studies

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SPECT and CT combinationSPECT and CT combination

Merges SPECT functional testing with Merges SPECT functional testing with CT anatomic landmark imagesCT anatomic landmark images

Statistics showStatistics show 25-30% change of treatment options 25-30% change of treatment options

from what would have been done with from what would have been done with SPECT aloneSPECT alone

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PETPET

Resolution is 2-10 better than SPECTResolution is 2-10 better than SPECT Radiopharmaceuticals Radiopharmaceuticals

Minimal alteration in homeostasisMinimal alteration in homeostasis Very small amounts usedVery small amounts used

Co-registration being done with CT & MRICo-registration being done with CT & MRI Almost all new machines are fused with a CT Almost all new machines are fused with a CT

scannerscanner

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