NMT 215 - Non-Imaging

Instrumentation Jimmy L. Council

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Course Description

This course covers the proper operation of various types of non-imaging equipment used in nuclear medicine. Emphasis is placed on principles of radiation detection, quality control procedures, various counting problems, and machine-specific operating procedures. Upon completion, students should be able to demonstrate the proper use of the devices discussed in the course.

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Evaluation

Quizzes 25% Lab 15% Mid-Term 30% Final 30%

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Review of Radioactive Decay Process Review of Interaction of Ionizing Radiation Basic Electronics

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Radioactive Decay Process

Alpha Beta

β−Positron β+

GammaElectron Capture Isomeric Transition

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Alpha

Helium nucleus (2protons, 2 neutrons) From nuclei of heavier atoms Charge of +2, Ionizes e- from outer shell until rest Travels approx. 4 cm in air

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Beta

High velocity electron ejected from nucleus May be negatively or positively charged N -> P + β− (Beta -) P -> N + β+ (Positron)

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Beta -

Can repel orbital electrons In tissue 1 MeV beta has a range of 0.42 cm Bremsstrahlung - Breaking radiation

Near contact with nucleus causing an ejection of a x-ray and secondary beta

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Positron Decay

May result in an annihilation reaction causing 2photons of 0.51 MeV being released at 180 degrees of each other

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Electron Capture

K or L shell electron is captured by the nucleus P + e- -> N X-rays can be produced filling the vacancy Auger electrons can be produced if an outer shell

electron is hit by a x-ray

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Isomeric Transition

Nucleus is in an excited state Release of energy in the form of a gamma photon 99mTc -> 99Tc

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Interactions with Matter

Scatter Photoelectric Effect Compton scatter Pair Production Photodisintegration

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Scatter

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Photoelectric Effect

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Compton Scatter

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Pair Production

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Photodisintegration

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Electricity and Magnetism

Electricity - flow of electrons Conductor - substance through which electrons

flow easily Insulator - substance that inhibit the flow of

electrons Good heat conductors are usually good electric

conductors

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Electricity and Magnetism

Semiconductor - material that under some conditions behaves as an insulator and others like a conductor

Electric Circuit - a closed path with a controlled resistance and conductor

Electric currents are measured in amperes Electric potential is measured in volts (v)

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Electricity and Magnetism

Electric resistance is measured in ohms (Ω) Ohms law - the voltage across the total circuit or

any portion of the circuit is equal to the current times the resistance

V=IR

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Electricity and Magnetism

Direct Current - DC - electrons flow in one direction along an electric conductor

Alternating Current - AC - Current in which electrons oscillate back and forth

Electric power measured in watts - one watt is equal to 1 amp of current flowing through an electric potential of 1 volt