Characteristics of Radiation for Imaging

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Learning Guide


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Objectives and Learning Activities

Imaging Modalities that use some form of energy or radiation:
Radiography and Fluoroscopy 
Computed Tomography (CT) 
Sonography (Ultrasound)
Radionuclide imaging (Nuclear Medicine)
Single photon emission computed tomography (SPECT) 
Positron emission tomography (PET) 
Magnetic resonance imaging (MRI) 

  •  Name the type of radiation or energy used to create images with each of modality listed above.
  •  Identify the modalities from the above list which use some form of electromagnetic radiation
  • Identify from the above list the modalities which use some form of ionizing radiation.
  • Give a general description of a photon.
  • Name the four distinguishing physical quantities associated with any photon.
  • Compare the velocity of x-ray, radio-frequency radiation, and light photons.
  • Describe the general relationship between the frequency and the energy of a photon
  • Describe the general relationship between the wavelength and the energy of a photon.
  • Identify the characteristic (photon energy, frequency, or wavelength) which is generally used to describe the
    radiation or energy for each modality listed above. 
  • Name and briefly describe the three types of energy which can be possessed by particles such as electrons. 
  • Identify the imaging modality which makes use of the rest-mass energy of electrons.
  • Briefly describe the concept of the quantum nature of radiation and how it applies to an x-ray beam.
  • Compare the energy of diagnostic x-ray and light photons by selecting a typical value for each with the appropriate units.
  • Describe the the general relationship between the energy of particle radiation (electrons) and particle velocity.
  • Compare a 100 keV photon and a 100 keV electron with respect to mass and velocity
  • Describe the relationship of the color of light to photon energy and wavelength. 
  • Describe the difference between an x-ray and a gamma photon if both have the same energy, for example 140 keV. 
  • Name and compare the size of at least two units used to express amounts of energy in radiology.
  • Describe the relationships of energy, power, and intensity.