Performance Testing in Computer Tomography using CATPHAN 600 <ul><ul><li>Asim Gilani </li></ul></ul><ul><ul><li>Radiation ...
CATPHAN 500 & 600
CATPHAN 500 & 600
Mounting
 
 
CATPHAN 600
CATPHAN 600
CTP 404 Slice Geometry and Sensitometry Module
CTP 404 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 25 mm </li></ul><ul><li>4 wire Ramps at an angle of 23 ° <...
CTP 404
CTP 404 <ul><li>Phantom position verification </li></ul><ul><li>Patient alignment system </li></ul><ul><li>Circular symmet...
Phantom Alignment Align phantom dots with the lasers
 
 
 
Phantom Alignment Scan 6 or 8 axial slices with minimum slice width Start 3 or 4 slices before the zero position
 
Phantom oriented to right side
Phantom oriented to left side
Phantom Tilted
 
Aligned Image
How to verify ? Switch ON grid to check the Phantom Alignment
 
 
CUATION Once the phantom is centered and aligned DO NOT touch or move the phantom by hand Only move or align it by table m...
Test 1: LASER Accuracy Align the phantom to lasers by moving the table Align all the dots to X, Y and Z LASERS as precisel...
Measurement of Z Axis Misalignment
Z-axis Misalignment Measure the distance between center of the phantom and center of the slice Multiple by 0.42 to find th...
X and Y Misalignment Switch ON grid and measure distance of the center of the grid to center of the image in X and Y direc...
X and Y Misalignment X = 4.61 x 0.42 1.9 mm Y = 3.26 x 0.42 1.4 mm
Test 2: Patient Alignment System Take Scanogram or Scout Take an axial Scan at the crosswire Measure the accuracy of the s...
 
 
Test 3: Circular Symmetry Take an axial Scan of the CTP 404 Image must be circular not elliptical Measure diameter of the ...
 
Distance Accuracy
Angle Accuracy
Test 4: Slice Width Accuracy Axially scan CTP 404 with different slice widths Measure slice with at (FWHM) ‏ Full Width at...
 
 
6.00  *  0.42  =  2.52 mm
Test 5: Slice Sensitometry Scan the phantom with different slice widths Measure CT Numbers of Different samples
CTP 404
 
Material  CT #  <ul><li>Air </li></ul><ul><li>PMP </li></ul><ul><li>LDPE </li></ul><ul><li>Water </li></ul><ul><li>Polysty...
Table Movement  <ul><li>Select axial scan with minimum slice width </li></ul><ul><li>Move table according to figure and sc...
Water and kV Accuracy <ul><li>Axially scan at different kV's </li></ul><ul><li>Verify that water CT number lies between -7...
Volume Verification The volume of five spheres ????
CTP 591 Bead Geometry Module
CTP 591 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>2 pairs of coarse ramps (39 beads ...
 
Slice Thickness Verification <ul><li>Make helical scan at different slice widths </li></ul><ul><li>Verify that all slices ...
 
Pitch Verification <ul><li>Make helical scan with different Pitches available </li></ul><ul><li>Verify the pitch by measur...
 
MTF Measurement <ul><li>The beads are for SSP and MTF measurements </li></ul><ul><li>We need software for these measuremen...
CTP 528 High Resolution Module
CTP 528 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>Radial gauge from 1 to 21 lines pe...
 
High Resolution Measurements
<ul><li>7 lp / cm visible </li></ul>
<ul><li>The beads are used for MTF and SSP measurements </li></ul><ul><li>HOW  ???????????? </li></ul>
CTP 515 Low Contrast Module
CTP 515 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>39 cylindrical rods </li></ul><ul>...
 
 
 
Contrast Verification <ul><li>(Measured Contrast) * (Smallest Diameter Discernible)    Constant </li></ul><ul><li>(1.0)  ...
Contrast Measurements <ul><li>Take ROI on 155 mm circles </li></ul><ul><li>Note down the CT # </li></ul><ul><li>Take ROI i...
 
CTP 486 Uniformity Module
CTP 486 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness > 40 mm </li></ul><ul><li>Uniform Module </li></ul><ul><li>C...
 
Artifact Analysis Change Window Width and level and observe any artifacts
Questions
Suggestions
Thanks
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QC of CT using Catphan 600

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This presentation is about using Catphan 600 phantom for Quality Control in Computer Tomography CT

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QC of CT using Catphan 600

  1. 1. Performance Testing in Computer Tomography using CATPHAN 600 <ul><ul><li>Asim Gilani </li></ul></ul><ul><ul><li>Radiation Protection Unit </li></ul></ul><ul><ul><li>Medical Physics Department </li></ul></ul><ul><ul><li>Dubai Hospital </li></ul></ul>08/07/09
  2. 2. CATPHAN 500 & 600
  3. 3. CATPHAN 500 & 600
  4. 4. Mounting
  5. 7. CATPHAN 600
  6. 8. CATPHAN 600
  7. 9. CTP 404 Slice Geometry and Sensitometry Module
  8. 10. CTP 404 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 25 mm </li></ul><ul><li>4 wire Ramps at an angle of 23 ° </li></ul><ul><li>5 Acrylic spheres </li></ul><ul><li>8 sensitometry samples </li></ul><ul><li>4 rods </li></ul>
  9. 11. CTP 404
  10. 12. CTP 404 <ul><li>Phantom position verification </li></ul><ul><li>Patient alignment system </li></ul><ul><li>Circular symmetry </li></ul><ul><li>Scan width </li></ul><ul><li>Sensitometry </li></ul>
  11. 13. Phantom Alignment Align phantom dots with the lasers
  12. 17. Phantom Alignment Scan 6 or 8 axial slices with minimum slice width Start 3 or 4 slices before the zero position
  13. 19. Phantom oriented to right side
  14. 20. Phantom oriented to left side
  15. 21. Phantom Tilted
  16. 23. Aligned Image
  17. 24. How to verify ? Switch ON grid to check the Phantom Alignment
  18. 27. CUATION Once the phantom is centered and aligned DO NOT touch or move the phantom by hand Only move or align it by table movements
  19. 28. Test 1: LASER Accuracy Align the phantom to lasers by moving the table Align all the dots to X, Y and Z LASERS as precisely as possible Scan axially with minimum slice thickness If the Image is same as previous one then LASERS are perfectly aligned OTHERWISE !
  20. 29. Measurement of Z Axis Misalignment
  21. 30. Z-axis Misalignment Measure the distance between center of the phantom and center of the slice Multiple by 0.42 to find the z-axis misalignment 4.99 x 0.42 = 2.1 mm
  22. 31. X and Y Misalignment Switch ON grid and measure distance of the center of the grid to center of the image in X and Y direction and multiply by 0.42
  23. 32. X and Y Misalignment X = 4.61 x 0.42 1.9 mm Y = 3.26 x 0.42 1.4 mm
  24. 33. Test 2: Patient Alignment System Take Scanogram or Scout Take an axial Scan at the crosswire Measure the accuracy of the scan
  25. 36. Test 3: Circular Symmetry Take an axial Scan of the CTP 404 Image must be circular not elliptical Measure diameter of the phantom in X & Y Measure distance between Teflon pins Additionally angle accuracy can be verified
  26. 38. Distance Accuracy
  27. 39. Angle Accuracy
  28. 40. Test 4: Slice Width Accuracy Axially scan CTP 404 with different slice widths Measure slice with at (FWHM) ‏ Full Width at Half Maximum Slice Thickness = FWHM * 0.42
  29. 43. 6.00 * 0.42 = 2.52 mm
  30. 44. Test 5: Slice Sensitometry Scan the phantom with different slice widths Measure CT Numbers of Different samples
  31. 45. CTP 404
  32. 47. Material CT # <ul><li>Air </li></ul><ul><li>PMP </li></ul><ul><li>LDPE </li></ul><ul><li>Water </li></ul><ul><li>Polystyrene </li></ul><ul><li>Acrylic </li></ul><ul><li>Delrin </li></ul><ul><li>Teflon </li></ul><ul><li>- 1000 </li></ul><ul><li>- 200 </li></ul><ul><li>- 100 </li></ul><ul><li>0 </li></ul><ul><li>- 35 </li></ul><ul><li>120 </li></ul><ul><li>340 </li></ul><ul><li>990 </li></ul>
  33. 48. Table Movement <ul><li>Select axial scan with minimum slice width </li></ul><ul><li>Move table according to figure and scan </li></ul><ul><li>Verify that you see the dot above </li></ul>
  34. 49. Water and kV Accuracy <ul><li>Axially scan at different kV's </li></ul><ul><li>Verify that water CT number lies between -7 to + 7 </li></ul>
  35. 50. Volume Verification The volume of five spheres ????
  36. 51. CTP 591 Bead Geometry Module
  37. 52. CTP 591 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>2 pairs of coarse ramps (39 beads each)‏ </li></ul><ul><li>1 pair of precision ramp (25 Beads each)‏ </li></ul><ul><li>2 Isolated beads for MTF and SSP </li></ul><ul><li>1 Steel wire of 50 µm diameter </li></ul>
  38. 54. Slice Thickness Verification <ul><li>Make helical scan at different slice widths </li></ul><ul><li>Verify that all slices are of same thickness </li></ul>
  39. 56. Pitch Verification <ul><li>Make helical scan with different Pitches available </li></ul><ul><li>Verify the pitch by measuring the center to center difference in adjacent scan and subtracting by the slice width </li></ul><ul><li>Turn grid ON for help </li></ul>
  40. 58. MTF Measurement <ul><li>The beads are for SSP and MTF measurements </li></ul><ul><li>We need software for these measurements </li></ul>
  41. 59. CTP 528 High Resolution Module
  42. 60. CTP 528 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>Radial gauge from 1 to 21 lines per cm </li></ul><ul><li>2 mm thick aluminum </li></ul><ul><li>2 beads of 0.28 mm 20 mm above and below the center in Y-axis & </li></ul><ul><li>2.5 mm and 10 mm past the center in Z-axis </li></ul>
  43. 62. High Resolution Measurements
  44. 63. <ul><li>7 lp / cm visible </li></ul>
  45. 64. <ul><li>The beads are used for MTF and SSP measurements </li></ul><ul><li>HOW ???????????? </li></ul>
  46. 65. CTP 515 Low Contrast Module
  47. 66. CTP 515 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness = 40 mm </li></ul><ul><li>39 cylindrical rods </li></ul><ul><li>3 contrasts, 0.3 %, 0.5 % & 1.0 % </li></ul><ul><li>3, 5, 7 & 40 mm length </li></ul><ul><li>2 to 9 & 15 mm diameter </li></ul>
  48. 70. Contrast Verification <ul><li>(Measured Contrast) * (Smallest Diameter Discernible)  Constant </li></ul><ul><li>(1.0) * (3.0) = 3.0 </li></ul><ul><li>(0.5) * (5.0) = 2.5 </li></ul><ul><li>(0.3) * (9.0) = 2.7 </li></ul>
  49. 71. Contrast Measurements <ul><li>Take ROI on 155 mm circles </li></ul><ul><li>Note down the CT # </li></ul><ul><li>Take ROI immediately around the circle </li></ul><ul><li>Subtract the 2 ROI's </li></ul><ul><li>It should be 10, 5 and 3 </li></ul>
  50. 73. CTP 486 Uniformity Module
  51. 74. CTP 486 <ul><li>Diameter = 150 mm </li></ul><ul><li>Thickness > 40 mm </li></ul><ul><li>Uniform Module </li></ul><ul><li>CT # between 0 to 2 % of water </li></ul>
  52. 76. Artifact Analysis Change Window Width and level and observe any artifacts
  53. 77. Questions
  54. 78. Suggestions
  55. 79. Thanks

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