Problems and Objectives for Learning, Discussion, Review, and Self Assessment

Energy and Radiation for Imaging

Resources and References
The Physical Principles of Medical Imaging
Online Textbook

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) 
Photography

  •  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. 
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