FSP Class-9 - Artifacts

The flashcards below were created by user flashsmilenet on FreezingBlue Flashcards.

  1. Artifact is...
    ... anomaly on the image
  2. Motion Artifact (list)
    • 1) Voluntary
    • 2) Involuntary
  3. Voluntary Artifact (def)
    • ghosting
    • manifest itself phase (horizontal) encoding direction
  4. Voluntary Artifact (correction)
    Good Pt-Tech communication
  5. Involuntary Artifacts (list)
    • Peristalsis - swallowing
    • Cardiac - heart beet
    • Respiration - breathing
  6. Involuntary Artifacts (corrections)
    • Gating techniques:
    •   1) Respiratory Gating
    •   2) Respiratory Triggering
    •   3) Cardiac Gating
  7. Respiratory Gating
    • Involuntary Artifacts correction
    • Image Upload
    • Bellows elastic strip in diagonal
    • Ask Pt to hold breath (17-27 sec)
    • Image Upload
    • system allows to start and end scan
    • Contraindications:
    • COPD and Astma
  8. Respiratory Triggering
    • Involuntary Artifacts correction
    • Reading from Transducer Clip
    • Image Upload
    • Free breathing automatically
    • R-wave - highest amplitude
    • Cardio Cycle - b/w 2 R-waves
    • Scan at R-wave (highest amplitude)
    • For abdomen, chest, pelvis
  9. If:
    RR=1000ms
    TD=60ms
    TW=40ms
    What is AST?
    AST=1000-(60+40)=900ms
  10. If HB = 60 B/min, how much TR is available?
    • 1) 60*1000=60,000ms
    • 2) 60,000ms/60s=1000ms
  11. Image Upload
    • P - Atrial Systole
    • GRS - Ventricular Systole
    • T - Ventricular Diastole
    • R - highest
  12. AST = ?
    • Cardiac Gating
    • Involuntary Artifacts correction
    • AST - Available Scan Time
    • AST = RR - (TD + TW)
  13. TD - TW - AST - ?
    • Cardiac Gating
    • Involuntary Artifacts correction
    • TD - Delay
    • TW - Window (10% off TD)
    • AST - Available Scan Time
    • AST = RR - (TD + TW)
  14. Image Upload
    • Cardiac Gating
    • Involuntary Artifacts correction
    • TD - Delay
    • TW - Window (10% off TD)
    • AST - Available Scan Time
    • AST = RR - (TD + TW)
  15. Cardiac Gating
    • Involuntary Artifacts correction
    • Reading from ECG Quadtrode
    • Image Upload
    • White  Black/Gray
    • Green  Red
    • Snow  Smock
    • Grass  Fire
    • Image Upload
    • P - Atrial Systole
    • GRS - Ventricular Systole
    • T - Ventricular Diastole
    • R - highest
    • Image Upload
    • TD - Delay
    • TW - Window (10% off TD)
    • AST - Available Scan Time
    • AST = RR - (TD + TW)
    • RR=1000ms
    • TD=60ms
    • TW=40ms
    • AST=1000-(60+40)=900ms

    • If HB = 60 B/min
    • How much TR is available?
    • 60*1000=60,000ms
    • 60,000ms/60s=1000ms
  16. Aliasing or Wraparound artifact
    • wrong FOV is used
    • Image Upload
  17. Aliasing artifact
    • Wraparound (another name)
    • wrong FOV is used
  18. Wraparound artifact
    • Aliasing (another name)
    • wrong FOV is used
  19. Image Upload
    • Aliasing or Wraparound artifact
    • wrong FOV is used
  20. Aliasing or Wraparound artifact elimination:
    • 1) ↥ FOV
    • 2) using No-Phase Wrap selected on the console
  21. Result of a phase shift difference b/w fat and water
    Chemical shift artifact
  22. Artifact as a small dark or bright border at the interfaces of bone, fat and muscle
    • Image Upload
    • Chemical shift artifact
  23. As stronger magnet as bigger this artifact
    Chemical shift artifact
  24. Chemical shift artifact
    • Image Upload
    • small dark or bright border at the interfaces of bone, fat and muscle
    • result of a Phase Shift Difference b/w fat and waterst
    • ronger magnet - bigger artifact
  25. Line along the spinal cord artifact
    • Truncation artifact
    • can mimics a Syrinx pathology
  26. Artifact as a line along the spinal cord
    • Image Upload
    • Truncation artifact
    • can mimics a Syrinx pathology
  27. Most common in C-spine, but also in T-spine artifact
    Truncation artifact
  28. Artifact mimics a Syrinx
    Truncation artifact
  29. Truncation artifact
    • line along the spinal cord
    • most common in C-spine, but also in T-spine
    • mimics a Syrinx pathology
    • Image Upload
  30. Splitting of the spinal cord pathology
    • Syrinx
    • occurs in C-T-spine
    • Truncation artifact mimics this pathology
  31. Syrinx
    • splitting of the spinal cord
    • pathology occurs in C-T-spine
    • Truncation artifact mimics this pathology
  32. Metal in the body or on clothing artifact
    Magnetic Susceptibility Artifact
  33. Magnetic Susceptibility Artifact
    • metal in the body or on clothing
    • Image Upload
  34. Image Upload
    • Magnetic Susceptibility Artifact
    • Metal in the body or on clothing artifact
  35. Pulse sequence better for Pt w prosthetic devices (metal)
    Spin Echo Pulse Sequences are better than Gradient Echoes
  36. Black lines across the image are seen in the inferior aspect of the axial slices
    Cross Excitation artifact
  37. Cross Excitation artifact
    • Image Upload
    • in axial planes of L-spine
    • lines must be parallel to the disk space
    • w the age and diseases it is not alwas the case - difficult to obtain true axis
    • black lines across the image will be seen in the inferior aspect of the axial slices
    • Solved by:  
    •   1) Apply an Interleave scan method  
    •   2) The slice gap must be reduced to 30% of the slice thickness
Author:
flashsmilenet
ID:
297189
Card Set:
FSP Class-9 - Artifacts
Updated:
2015-03-21 22:07:04
Tags:
FSP Class Artifacts
Folders:
FSP Class
Description:
FSP Class-9 - Artifacts
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