PHOTOSTIMULABLE-PHOSPHOR PLATE (PSP)
RESPONSES IN COMPUTED RADIOGRAPHY AT
EXPOSURE FACTOR ASCENT RELATED TO TUBE
VOLTAGE A...
INTRODUCTION
 Accuracy of control panel-radiation output
become one of aim for quality control in
radiology services.
 G...
Tube voltage accuracy and linearity of output
from x-ray machine use photostimulable-
phosphor plate responses which is ba...
AIM OF RESEARCH
Understanding influence of the gradual ascent
of exposure factor in x-ray machine to
photostimulablephosph...
RESEARCH PROFIT
Giving an alternative way for the Hospital that held
Computed Radiography System to perform
compliance tes...
COMPUTED RADIOGRAPHY
BASIC OF RESEARCH
COMPUTED RADIOGRAPHY RESPONSES
1. EXPOSURE INDEX
2. DEVIATION INDEX
3. IEC STANDARD 62494-1
4. MEAN GRAY VALUE
RESEARCH INSTRUMENTATION
&MATERIAL
• RADIODIAGNOSTIC MACHINE
• COMPUTED RADIOGRAPHY
(CARESTREAM)
• X-RAYANALYZER PIRANHA
•...
RESEARCH METHODE
Compliance Test :
1. Tube Voltage Accuracy
2. Tube Current Linearity
3. X-Ray Reproducibility
Examination...
GETTING PRIMARY DATA
CR
Positioning
CR Expose CR Reading
Exposure
indicator
Value entry
Analyzing
digital
image
ImageJ1.46...
RESULT OF THE RESEARCH
COMPLIANCE TEST RESULT:
Tube Voltage Accuracy:
Inaccuracy maximum is 1,4 % in 90 kVp
Tube Current L...
Relation of linear ascent in tube voltage (kVp) with steady
tube current-exposure time (mAs) to Exposure Index
y = 1712.ln...
y = 19.06x - 933.8
R² = 0.952
y = 39.41x - 1949.
R² = 0.962
y = 78.21x - 3820.
R² = 0.954
y = 149.1x - 7341.
R² = 0.940
y ...
Relation of linear ascent in tube voltage (kVp) with steady
tube current-exposure time (mAs) to Deviation Index
y = 18.19l...
Relation of linear ascent in tube voltage (kVp) with steady
tube current-exposure time (mAs) to Mean Gray value
y = 909.5l...
Relation of linear ascent in tube current-exposure time (mAs) with steady
tube voltage (kVp) to Exposure Index
y = 344.3ln...
Relation of linear ascent in tube current-exposure time (mAs) with steady
tube voltage (kVp) to IEC Standard
y = 141.5x - ...
Relation of linear ascent in tube current-exposure time (mAs) with steady
tube voltage (kVp) to Deviation Index
y = 4.330l...
Relation of linear ascent in tube current-exposure time (mAs) with steady
tube voltage (kVp) to Mean Gray Value
y = 215.4l...
Coefficient of Linearity |X1 – X2| ≤ 0.1 (X1 + X2)
Result of Measuring of mAs linearity by Piranha analyzer
achieved maxim...
CONCLUSION
• Exposure indicator in CR that used in this
research is calibrated because it has linear
responses to the radi...
CONCLUSION
• Determining of tube voltage accuracy with an
Exposure indicator can be done.
• Mean gray value is able to be ...
SUGESTION
• Doing research to density of film print out in
same condition as the research.
• Doing research for the others...
THANKS FOR THE ATTENTION
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tube voltage accuracy and linearity output using exposure indicator and mean gray value

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tube voltage accuracy and linearity output using exposure indicator and mean gray value

  1. 1. PHOTOSTIMULABLE-PHOSPHOR PLATE (PSP) RESPONSES IN COMPUTED RADIOGRAPHY AT EXPOSURE FACTOR ASCENT RELATED TO TUBE VOLTAGE ACCURACY & OUTPUT LINEARITY OF X-RAY MACHINE DWI ADHIANTO 24040112150010 MEDICAL PHYSICS TRANSFER PROGRAM SCIENCE AND MATH FACULTY DIPONEGORO UNIVERSITY SEMARANG 2014
  2. 2. INTRODUCTION  Accuracy of control panel-radiation output become one of aim for quality control in radiology services.  General using of Computed Radiography in Indonesia .  Linear response of imaging plate to x-ray intensities
  3. 3. Tube voltage accuracy and linearity of output from x-ray machine use photostimulable- phosphor plate responses which is basic of Computed Radiography technology PROBLEM FORMULATION
  4. 4. AIM OF RESEARCH Understanding influence of the gradual ascent of exposure factor in x-ray machine to photostimulablephosphor plate responses related to tube voltage accuracy and linearity of output x-ray machine.
  5. 5. RESEARCH PROFIT Giving an alternative way for the Hospital that held Computed Radiography System to perform compliance test by using imaging plate responses.
  6. 6. COMPUTED RADIOGRAPHY
  7. 7. BASIC OF RESEARCH
  8. 8. COMPUTED RADIOGRAPHY RESPONSES 1. EXPOSURE INDEX 2. DEVIATION INDEX 3. IEC STANDARD 62494-1 4. MEAN GRAY VALUE
  9. 9. RESEARCH INSTRUMENTATION &MATERIAL • RADIODIAGNOSTIC MACHINE • COMPUTED RADIOGRAPHY (CARESTREAM) • X-RAYANALYZER PIRANHA • ALLUMINIUM STEPWEDGE
  10. 10. RESEARCH METHODE Compliance Test : 1. Tube Voltage Accuracy 2. Tube Current Linearity 3. X-Ray Reproducibility Examination Table X-ray Tube Detector SID
  11. 11. GETTING PRIMARY DATA CR Positioning CR Expose CR Reading Exposure indicator Value entry Analyzing digital image ImageJ1.46r X-rar Tube STEPWEDGE SID Imaging Plate Examination table
  12. 12. RESULT OF THE RESEARCH COMPLIANCE TEST RESULT: Tube Voltage Accuracy: Inaccuracy maximum is 1,4 % in 90 kVp Tube Current Linearity: Maximum Difference in mGy/mAs at 0,3 % X-Ray Reproducibility: Coefficient variation of voltage reproducibility is 0,01 & Exposure reproducibility is 0,01
  13. 13. Relation of linear ascent in tube voltage (kVp) with steady tube current-exposure time (mAs) to Exposure Index y = 1712.ln(x) - 5669. R² = 0.979 y = 1785.ln(x) - 5720. R² = 0.983 y = 1868.ln(x) - 5815. R² = 0.967 y = 1870.ln(x) - 5574. R² = 0.971 y = 1872.ln(x) - 5300. R² = 0.962 y = 1926.ln(x) - 5275 R² = 0.959 0 500 1000 1500 2000 2500 3000 3500 40 50 60 70 80 90 100 ExposureIndex Tube Voltage (kVp) 0,5 mAs 1 mAs 2 mAs 4 mAs 8 mAs 16 mAs
  14. 14. y = 19.06x - 933.8 R² = 0.952 y = 39.41x - 1949. R² = 0.962 y = 78.21x - 3820. R² = 0.954 y = 149.1x - 7341. R² = 0.940 y = 320.8x - 15791 R² = 0.952 y = 633.6x - 31140 R² = 0.959 0 5000 10000 15000 20000 25000 30000 40 50 60 70 80 90 100 IECStandard Tube Voltage (kVp) 0,5 mAs 1 mAs 2 mAs 4 mAs 8 mAs 16 mAs Relation of linear ascent in tube voltage (kVp) with steady tube current-exposure time (mAs) to IEC Standard
  15. 15. Relation of linear ascent in tube voltage (kVp) with steady tube current-exposure time (mAs) to Deviation Index y = 18.19ln(x) - 78.09 R² = 0.980 y = 18.02ln(x) - 74.29 R² = 0.991 y = 18.02ln(x) - 71.19 R² = 0.979 y = 18.42ln(x) - 70.04 R² = 0.987 y = 18.38ln(x) - 66.67 R² = 0.982 y = 18.15ln(x) - 62.74 R² = 0.986 -10 -5 0 5 10 15 20 25 40 50 60 70 80 90 100 Deviationindex Tube Voltage (kVp) 0,5 mAs 1 mAs 2 mAs 4 mAs 8 mAs 16 mAs
  16. 16. Relation of linear ascent in tube voltage (kVp) with steady tube current-exposure time (mAs) to Mean Gray value y = 909.5ln(x) - 2370. R² = 0.905 y = 672.0ln(x) - 1224. R² = 0.846 y = 442.2ln(x) - 103.3 R² = 0.696 y = 625.2ln(x) - 794.4 R² = 0.738 y = 461.0ln(x) + 8.540 R² = 0.829y = 393.6ln(x) + 362.5 R² = 0.405 0 1000 2000 3000 40 50 60 70 80 90 100 MeanGrayValue Tube Voltage (kVp) 0,5 mAs 1 mAs 2 mAs 4 mAs 8 mAs 16 mAs
  17. 17. Relation of linear ascent in tube current-exposure time (mAs) with steady tube voltage (kVp) to Exposure Index y = 344.3ln(x) + 1198. R² = 0.998 y = 387.3ln(x) + 1641. R² = 0.999 y = 381.0ln(x) + 1940. R² = 0.999 y = 376.6ln(x) + 2076 R² = 0.999 y = 387.7ln(x) + 2269. R² = 0.999 0 1000 2000 3000 4000 0 5 10 15 20 ExposureIndex Current-Exposure Time (mAs) 50 kVp 60 kVp 70 kVp 80 kVp 90 kVp
  18. 18. Relation of linear ascent in tube current-exposure time (mAs) with steady tube voltage (kVp) to IEC Standard y = 141.5x - 11.36 R² = 0.999 y = 400.6x - 25.48 R² = 0.999 y = 726.5x + 23.91 R² = 0.999 y = 1090.x - 157.5 R² = 0.999 y = 1785.x - 49.45 R² = 0.999 0 5000 10000 15000 20000 25000 30000 0 5 10 15 20 IECStandard Current-Exposure Time (mAs) 50 kVp 60 kVp 70 kVp 80 kVp 90 kVp
  19. 19. Relation of linear ascent in tube current-exposure time (mAs) with steady tube voltage (kVp) to Deviation Index y = 4.330ln(x) - 4.352 R² = 0.999 y = 4.460ln(x) - 0.099 R² = 0.999 y = 4.279ln(x) + 2.939 R² = 0.999 y = 4.422ln(x) + 4.342 R² = 0.999 y = 4.387ln(x) + 6.588 R² = 0.999 -10 -5 0 5 10 15 20 25 0 5 10 15 20 DeviationIndex Current-Exposure Time (mAs) 50 kVp 60 kVp 70 kVp 80 kVp 90 kVp
  20. 20. Relation of linear ascent in tube current-exposure time (mAs) with steady tube voltage (kVp) to Mean Gray Value y = 215.4ln(x) + 1417. R² = 0.971 y = 153.9ln(x) + 1525. R² = 0.882y = 175.2ln(x) + 1562 R² = 0.988 y = 91.50ln(x) + 1730. R² = 0.860 y = 160.0ln(x) + 1846. R² = 0.959 0 500 1000 1500 2000 2500 0 2 4 6 8 10 12 14 16 18 MeanGrayValue Current-Exposure Time (mAs) 50 kVp 60 kVp 70 kVp 80 kVp 90 kVp
  21. 21. Coefficient of Linearity |X1 – X2| ≤ 0.1 (X1 + X2) Result of Measuring of mAs linearity by Piranha analyzer achieved maximum Coefficient of Linearity amount 0,0031 Result of Calculating IEC Standard/mAs achieved Coefficient of Linearity amount 0,005-0,061 y = 0.051x - 0.000 R² = 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 5 10 15 20 Eksposur(mGy) Arus tabung-Waktu penyinaran (mAs)
  22. 22. CONCLUSION • Exposure indicator in CR that used in this research is calibrated because it has linear responses to the radiation output compare to result of compliance test with Piranha Analyzer • Linearity of mAs can be decided with a calibrated imaging plate • Deciding a coefficient of mAs linearity can be done with IEC Standard/mAs data.
  23. 23. CONCLUSION • Determining of tube voltage accuracy with an Exposure indicator can be done. • Mean gray value is able to be an indicator of mAs linearity because has a coefficient of correlation more than 0,94.
  24. 24. SUGESTION • Doing research to density of film print out in same condition as the research. • Doing research for the others CR vendor.
  25. 25. THANKS FOR THE ATTENTION
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