Charlotte Jakes
Test por , creado hace más de 1 año

Only a few questions on the history and physics of imaging - key words found in Quizlet

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Charlotte Jakes
Creado por Charlotte Jakes hace más de 4 años
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Imaging Techniques

Pregunta 1 de 25

1

Who discovered the x-ray in 1895?

Selecciona una de las siguientes respuestas posibles:

  • Wilhelm Rongten

  • Johann Radon

  • Hounsfield

  • Oldendorf

Explicación

Pregunta 2 de 25

1

Lossy compression file formations should never be used to store medical images.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 3 de 25

1

With what piece of apparatus were x-rays discovered?

Selecciona una de las siguientes respuestas posibles:

  • Crooke's tube with barium platinocyanide

  • Crooke's tube with phosphorus

  • A 14C isotope and photographic film

  • A heated sample of helium

Explicación

Pregunta 4 de 25

1

Why is iodine a good contrast agent for x-ray imaging?

Selecciona una de las siguientes respuestas posibles:

  • High attenuation

  • Long radioactive half life

  • Only need a small amount

  • Produces pink colouration of photographic paper

Explicación

Pregunta 5 de 25

1

X-rays are produced when high speed electrons strike a target material. The energy of these electrons can be converted to what, in terms of what is useful in medicine?

Selecciona una de las siguientes respuestas posibles:

  • Light photons

  • Gamma rays

  • Alpha particles

  • Microwaves

Explicación

Pregunta 6 de 25

1

Which factors of tissues allow us to distinguish between different tissues on an x-ray image?

Selecciona una o más de las siguientes respuestas posibles:

  • Thickness/distance from source - the longer the distance travelled, the lower the intensity of x-rays detected

  • Attenuation - a measure of the material's ability to attenuate x-rays (higher attenuation = brighter image)

  • Oxygen concentration in the tissue

  • Fluid content of the tissue

Explicación

Pregunta 7 de 25

1

Tissues who are more attenuating of x-rays appear brighter on x-rays (i.e. bones are highly attenuating so appear bright white)

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 8 de 25

1

Which generation of CT scan do modern systems use?

Selecciona una de las siguientes respuestas posibles:

  • Generation 1 - dual motion pencil beam scanner in a translate-rotate mechanism

  • Generation 2 - dual motion narrow fan beam in a translate-rotate mechanism

  • Generation 3 - single motion with a fan beam and rotating detector and source in a rotate-rotate mechanism

  • Generation 4 - fan beam with rotating source only and stationary-rotate mechanism

  • Generation 5 - scanning electron beam with stationary-stationary mechanism

Explicación

Pregunta 9 de 25

1

Rellena los espacios en blanco para completar el texto.

Fill in the blanks to give the type of ionising radiation based off the property.
radiation is stopped by paper.
radiation is not stopped by paper but is stopped by plastic.
radiation is not stopped by paper or plastic but is stopped by concrete/steel/lead.

Explicación

Pregunta 10 de 25

1

Alpha decay occurs in natural radioactive elements heavier than lead (i.e. having a relative mass of over 81)

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 11 de 25

1

In beta-minus decay, what does a neutron break down into?

Selecciona una de las siguientes respuestas posibles:

  • Proton and electron

  • Two neutrons

  • Two electrons

  • Two protons

Explicación

Pregunta 12 de 25

1

In beta-minus decay, the atomic number and mass both increase by 1.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 13 de 25

1

In beta-plus decay, a proton breaks down into what?

Selecciona una de las siguientes respuestas posibles:

  • A neutron and a positron

  • A proton and neutron

  • A proton and electron

  • Two protons

Explicación

Pregunta 14 de 25

1

Why is alpha radiation not suitable for medical imaging?

Selecciona una de las siguientes respuestas posibles:

  • Won't be detectable outside of the body

  • Not safe for use inside the body

  • Releases too much thermal energy

  • Isn't found in non-toxic mediums

Explicación

Pregunta 15 de 25

1

What happens when a positron and an electron meet?

Selecciona una de las siguientes respuestas posibles:

  • They are converted into two gamma photons travelling in opposite directions

  • They form two protons which travel in the same direction

  • The positron is converted into an electron and the two orbit one another

  • They form one neutron

Explicación

Pregunta 16 de 25

1

In isomeric transition, the mass, atomic number and charge of the nucleus all remain the same.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 17 de 25

1

Radioactive isotopes with long half lives are not suitable for use in medical imaging.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 18 de 25

1

Which radioactive isotope do we commonly use in medical imaging due to its half life of around 6 hours and its ability to be made in a lab?

Selecciona una de las siguientes respuestas posibles:

  • Technetium

  • Phosphorus

  • Platinum

  • Tungsten

Explicación

Pregunta 19 de 25

1

Why can we use the 18F isotope to monitor metabolism in tissues?

Selecciona una de las siguientes respuestas posibles:

  • 18F can be incorporated into fluorodeoxyglucose which the body treats as standard glucose

  • 18F emits radiation in high carbon dioxide concentrations

  • 18F emits radiation in high oxygen concentrations

  • 18F reacts with acetyl CoA, emitting radiation

Explicación

Pregunta 20 de 25

1

What type of radiation does the 18F isotope emit?

Selecciona una de las siguientes respuestas posibles:

  • Beta-plus (positrons)

  • Beta-minus (electrons)

  • Alpha (alpha particles)

  • Gamma

Explicación

Pregunta 21 de 25

1

Rellena los espacios en blanco para completar el texto.

Fill in the blanks to describe the physics of MRI scanning.
Protons have the physical property of - they spin on their axes oriented in different directions.
When placed inside a magnetic field, the protons align and become .
Some protons will spin in a direction, others in a south-north direction.
In the MRI scanner, a second electromagnet flips the protons off their axes, usually by degrees.
The of the coil must exactly match the at which the protons are spinning.
When we turn off the second electromagnet and the proton returns to its spin and releases signals which can be detected.
Different tissues have different densities of so take different lengths of time to return to rest - these relaxation time differences form contrasting images.

Explicación

Pregunta 22 de 25

1

Why do MRI images not show bone?

Selecciona una de las siguientes respuestas posibles:

  • Bone has low hydrogen content

  • Bone has high calcium content

  • Protons in bone do not have spin

  • Bone has high hydrogen content

Explicación

Pregunta 23 de 25

1

Rellena los espacios en blanco para completar el texto.

Fill in the blanks below to describe the principles of ultrasound imaging.
A short ultrasound pulse is emitted and a detector 'listens' for a pulse. The time between emitting a pulse and receiving a response tells us how far away the pulse was when it was . The energy of the pulse tells us how much the energy has in the tissue - the properties of the tissue determine this.

Explicación

Pregunta 24 de 25

1

What did Ansell and Rotblat do in 1948?

Selecciona una de las siguientes respuestas posibles:

  • Produce the first image of a thyroid using radioactive iodine

  • Discovered the X-ray

  • Invented the hydrophone for locating icebergs based on pulse-echo principles

  • Discovered radioactivity

Explicación

Pregunta 25 de 25

1

Langevin invented the hydrophone to detect icebergs using pulse-echo physics ib 1915 following the Titanic disaster.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

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