1. Introduction to Radiology
What you need to know about imaging to get through the next four years
Mark Chambers D.V.M., Ph.D., M.D.

2. Topics of Discussion How to approach reading any image
What are the different imaging modalities
What imaging modality is this
Tips and tricks for image interpretation
Practice! Practice! Practice!

3. How to Approach Reading any Image
Identify the patient
When was the image taken
Are these the proper images
The five densities
Are the images technically adequate

4. Identify the Patient Always look for the patient name and/or number
Even if the film came out of the “right” folder
If something seems “wrong”, double check

5. When was the Image Taken
Observe dates and times closely, especially with serial images
Date “stickers” (color keyed)

6. Are these the Proper Images
Correct type of study
Correct / complete views
Correct limb
Contrast

7. The Five Densities
Metal
Bone
Soft tissue (water)
Fat
Gas

8. Are the Images Technically Adequate
Exposure
Development / display
Positioning
Proper contrast
Artifacts
Movement
Interference

9. What are the Different Imaging Modalities
Radiography “plain films”
Computed axial tomography “CT”
Magnetic resonance imaging “MRI”
Ultrasound “US”
Interventional radiology “angio”

10. Radiography Also called “plain films” or “standard films”
Image formed using broad beam ionizing radiation
The image formed is related to the subjects density
May involve the use of contrast agents
Iodinated
Barium
Air

11. Computed Axial Tomography
Also called CAT scanning or “CT”
Image formed using a rotating thin beam(s) of ionizing radiation
Image “slices” reconstructed by computation
The image formed is related to the subjects density
Image display on computer or multiple films
New technology is multislice helical scanner

12. Magnetic Resonance Imaging
Also called “MRI” (used to be NMRI)
Image formed by transmitting and receiving radio waves inside a high magnetic field
Image “slices” reconstructed by computation
The image formed is related to:
Scanner settings
Patient hydrogen density
Patient hydrogen chemical/physical environment
Image display on computer or multiple films

13. Ultrasound Also called “sono” or “echo” or “US”
Image formed by transmitting and receiving high frequency sound waves
Image “slices” reconstructed by computation
The image formed is related to interfaces between tissue areas of differing sound transmission characteristics
Image display on computer or multiple films

14. Interventional Radiology
Also called angiography or “angio” or “IR”
Image formed using broad beam ionizing radiation (fluoroscopy)
Images acquired using digital detector and processed by computer
The image formed is related to the subjects density
Usually involves the use of iodinated contrast agents and long catheters
Many varied techniques including the use of CT or MRI
Image display on computer or multiple films

15. What Imaging Modality is this
Is it plain film or interventional
Is it CT or MRI

16. Plain Film or Interventional
May look very similar
Angio studies usually printed on large sheet film like CT or MRI
Will usually see catheter or needle, often with contrast in IR studies

18. CT or MRI CT images are tissue density related
Brightness and contrast may vary
Bone is brighter than fat
MRI is not density related
Bone is darker than other tissues

22. Tips and Tricks for Image Interpretation
The “quick read” technique
Scrolling through axial images

23. The “quick read” Technique
Why did you order the image
What did you expect to see
Do you see it
Now start over fresh

24. Scrolling Through Axial Images
Rapid paging through sequential images
On computer display of CT and MRI images
Allows you to follow long/large structures
Helps rapidly identify small higher contrast areas

25. Practice! Practice! Practice!
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