Study Guide - Exam three - SPECT Imaging, acquisition, filtering, and quality control

  1. Example Filtered Back projection
    1. Why does FBP have greater noise when compared to planar?
    2. What is the star defect?
    3. How is it eliminated?
    4. Define the role of a Fourier reconstruction
  2. Frequency Domain
    1. Define it
    2. Compare to MTF
    3. Define the parts of the domain: noise, bkg, and true counts
  3. Nyquist Frequency
    1. Define it
    2. Calculate it
    3. What causes aliasing?
  4. Filtering and image reconstruction
    1. Pre-filter - why?
    2. Parts of a filter: order, power, windowing, critical frequency
    3. Types of filters: low/high/band pass, restoration, surface rendering, dynamic triangulation
    4. Different slices in a SPECT scan
  5. Iterative Reconstruction
    1. Define and compare to FBP
    2. Understand the basic steps of IR
    3. Compare OSEM to MLEM
  6. SPECT acquisition
    1. Define the imaging characteristics
    2. Define particle volume effect
    3. Consider: zoom, collimation, matrix, energy window, type of orbit
  7. Attenuation Correction
    1. Chang and the homogenous effect
    2. Line source - two and three heads
    3. 153Gd vs CT
    4. How does CT work in applying AC
  8. Scatter and attenuation correction
    1. Discuss how gamma-rays interact in a media at the atomic level
    2. Compare 140 keV to 511 keV
    3. Compare bone to water to air
    4. What is the issue with scatter at depth with SPECT?
    5. How does Chang work with scatter - when can (cannot) it be applied?
    6. Why is it better to use an ultra-high resolution collimator over a high resolution collimator?
    7. How does applying a rod source or CT scatter correct for attenuation?
    8. Understand the concept of resolution recovery
  9. Scatter Correction
    1. How do you correct for scatter when there are multiple densities?
    2. Discuss rod/line source - TBAC
    3. What is the difference in a TBAC correction - 3-head vs. 2-head - camera
    4. Type of radioactive source
    5. How does it correct of scatter?
    6. Discuss CT use in scatter correction
      1. What is down sampling?
      2. How is segmentation used in the AC map?
      3. Monochromatic vs polychromatic
      4. Scaling - more a PET thing - why?
      5. When and why do you apply a reference scan?
      6. What is beam hardening?
    7. Scatter compensation - know the basic concepts
  10. Quality Control
    1. Compare and contrast - Intrinsic to Extrinsic uniformity
    2. What are the advantages and disadvantages of
      1. Refillable floods
      2. 57Co sheet source
      3. Point source
      4. Identify examples of flood uniformity and examine its quality
    3. Discuss the procedure COR
      1. What is the difference between a COR and a AOR?
      2. How does COR compensation of the X-axis offset?
      3. What is an example of a Y-axis offset?
      4. Identify good vs. bad COR data
    4. Briefly discuss then procedure for defining detector head stability - why should this be done?
    5. Jaszczak phantom
      1. What are the components of it and how do they relate to a SPECT QC
      2. Calculate system volume sensitivity?
  11. Review the types of artifacts seen a SPECT scan
    1. Ray - note how this can occur in an MPI study
      1. Ring
      2. Motion - 180 vs 360 degree
      3. Blending of motion and ray
      4. Truncation

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