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Standard edge detection algorithms versus conventional auto-contouring used for a three-dimensional rigid CT-CT matching
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M. Mohammadi   , Sh. Nabavi |
| , mohammadi@umsha.ac.ir |
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Abstract: (10985 Views) |
| Background: To reduce uncertainties of patient
positioning, the Computerized Tomography (CT)
images acquired at the treatment planning time can
be compared with those images obtained during
radiation dose delivery. This can be followed during
dose delivery procedure as Image Guided
radiotherapy (IGRT) to verify the prescribed radiation
dose delivery to the target as well as to monitor
radiation dose constraints for organ at risks located
in the vicinity of tumour region. A method was
developed to compare registered rigid CT images
with those acquired during treatment procedure.
Materials and Methods: Several CT images were
acquired for a typical Rando phantom at head and
neck region. Selecting the CT images as reference,
they were then manipulated in transitional and
rotational directions. The differences in transited and
rotated images were evaluated by edge detection
algorithms and conventional automatic contouring
used in most of current treatment planning systems.
Setting of standard edge detection algorithms was
investigated and the appropriate one was selected.
Applying the selected optimized standard edge
detection algorithm and conventional auto-contouring
on CT image differences, the characteristics of
methods were evaluated. Results: Results show that
1 pixel difference in transition and 1 degree in
rotation can be recognized for inhomogeneous
regions. A significant variation was detected at the
bony-soft tissue and air-soft tissue conjunction
regions. Conclusion: The results obtained from the
current study are comparable with those reported
using Chamfer algorithm. It is concluded that the
current method, can be used to control patient
positioning in radiotherapy sessions as a part of
Image guided radiotherapy protocols. Iran. J. Radiat.
Res., 2012 10(3‐4): 123‐130
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| Keywords: CT-CT matching, Edge detection algorithms, Image registration, Image guided Radiotherapy. |
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Full-Text [PDF 1339 kb]
(3678 Downloads)
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Type of Study: Original Research |
Subject:
Radiation Biology
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