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

Blur, Visibility of Detail, and Resolution

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

  • Describe the general appearance of a significantly blurred image

  • Describe the relationship between blur and visibility of anatomical detail and small objects.

  • Identify the principle cause of blurred images in human vision

  • Identify two causes of blurred images in photography.

  • Describe three different blur shapes encountered in medical imaging and identify at least one source for each. 

  •  Discuss the concept of equivalent blur. 

  • Describe the relationship between blur and image un-sharpness

  • Describe the concept of spatial resolution and how it is expressed (units). 

  • Explain how blurring affects spatial resolution

  • Explain why spatial resolution is often used to describe the capabilities of a medical imaging system or it's components. 

  • Describe the general process of measuring the resolution of an x-ray imaging system.

  • Draw and compare a pair of modulation transfer function (MTF) curves for two systems which produce different amounts of blurring. 

  • Explain how a MTF curve relates to visibility of anatomical detail

  • Compare the general blur values and visibility of detail for the different medical modalities