Outline and Guide for Learning

Image Noise

Resources and References
The Physical Principles of Medical Imaging
Online Textbook
Visuals for Discussion

• Introduction and Overview 

• Visual Noise in Images
  What does it look like
  Other names for visual noise
  Recognizing noise in clinical images
   

• Effect of Noise on Visibility
  Relationship to object contrast
  Relationship to object size
   

• Sources of Image Noise
  X-ray Imaging
  Random distribution of x-ray photons (most significant)
  Receptor structure (crystals and film grains)
  Radionuclide Imaging
  Random distribution of  photons (most significant)
  MRI
  RF signal strength in relation to noise energy
   

• The Statistics of Radiation Photons
  Random nature of photons
  Statistical distributions
  Standard deviations
  Relationship of standard deviation to mean number of photons and exposure
   

• Quantum Noise
  Concept of quantum noise
  Relationship to concentration of photons
  Concept and significance of quantum sink
   

• Relationship of Noise to Exposure
  Relationship to receptor sensitivity (speed)
  Optimizing noise with patient exposure
  Characteristics of screen/film receptors that determine noise
  Characteristics of digital radiographic receptors that determine noise
   

• Relationship of Noise to Image Detail
  General effect of image blurring on noise
  Effect of digital image pixel size
   

• Effect of Image Display Contrast on Visibility of Noise
  Film contrast characteristics
  Digital image windowing
   

• Image Processing to Reduce Noise
  Blurring and pixel averaging
  Averaging or integrating a series of images
   

• Summary