Sean Lauber:AMIRA - Creating Label Fields by Lung Segmentation: Difference between revisions
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In order to evaluate changing densities in the lung of an affected animal, you need to separate the lung portion of the CT scan from the rest of the CT scan. This is done by creating a lung "label field". One method of generated a lung label is by a process called "thoracic segmentation". | In order to evaluate changing densities in the lung of an affected animal, you need to | ||
separate the lung portion of the CT scan from the rest of the CT scan. This is done by | |||
creating a lung "label field". One method of generated a lung label is by a process | |||
called "thoracic segmentation". | |||
The idea is to color in sections of the lungs, using the ribs as a guide, and interpolate | |||
the label between sections. This will generate a 3D segmentation of the lung which can | |||
subsequently be analyzed for density values by histogram analysis. | |||
1. Open the relevant .raw file | 1. Open the relevant .raw file | ||
2. Adjust the parameters accordingly. <b> For | 2. Adjust the parameters accordingly. <b> For data from the MCPTI I use the following | ||
parameters:</b> | |||
[[Image:Amira-lung label00.png]] | |||
3. Then open the Segmentation Editor (see the cursor): | |||
[[Image:Amira-lung label01.png]] | |||
4. In the Segmentation Editor, open a New Label Data file (see the cursor), and the lung | |||
CT data will load: | |||
[[Image:Amira-lung label02.png]] | |||
5. Add a New Material (see cursor, in this case Material2) so you can add label data to a | |||
material file. | |||
[[Image:Amira-lung label03.png]] | |||
6. I like to adjust the Data Window to better show the CT data | |||
[[Image:Amira-lung label04.png]] | |||
7. Select the Paint tool so you can begin coloring in the lung label. I like to use a | |||
point size of 60 to begin, and as I move on increase the size to 100. | |||
[[Image:Amira-lung label05.png]] | |||
8. Bring up the position of the CT scan towards the head (either scroll up/down over the | |||
CT image or adjust the bar directly below the CT image). Position the image to show the | |||
first set of ribs (see figure) and color in the area (shown in red in the figure, this | |||
should take a single click of the mouse). | |||
[[Image:Amira-lung label06.png]] | |||
9. To clean up the image, hold down ctrl and click the mouse to delete label, use this | |||
feature to exclude the region surrounding the spinal cord. | |||
[[Image:Amira-lung label07.png]] | |||
10. Scroll down approximately 3 ribs (watch the ribs emerge from the spinal cord area), | |||
then color in this lung section. Delete the label surrounding the spinal cord (as shown | |||
in the figure). | |||
[[Image:Amira-lung label08.png]] | |||
11. Next we want to interpolate the label that you made at the first set of ribs to the | |||
label you just made at this 4th set of ribs. To do this go to Selection/Interpolate or | |||
press ctrl-I. Scroll up and down to verify that the interpolation worked. | |||
12. From the 4th set of ribs, go down another 3 sets. Color in this area (I like to use | |||
paint brush size 100 from here on), remove spine label, and interpolate. | |||
[[Image:Amira-lung label09.png]] | |||
13. From this 7th set of ribs, go down until you see the diaphragm begin to appear. This | |||
is located just below the heart. Color in this area, remove spine, and interpolate. | |||
[[Image:Amira-lung label10.png]] | |||
14. From the region of the diaphragm, scroll down until you don't see any lung left. | |||
Color in this region as indicated, remove spine and interpolate. You don't want to color | |||
the whole of this region because much of it is not lung, and you want to color it in in | |||
the indicated shape so when it interpolates upwards it forms the desired shape. | |||
[[Image:Amira-lung label11.png]] | |||
15. The lung segmentation is now complete! | |||
16. To save the label, add the label to the material (Material2) by clicking the + sign | |||
(see cursor). <b> Make sure you have Material2 highlighted, if you have nothing | |||
highlighted, then the label you've just created will be lost.</b> | |||
[[Image:Amira-lung label12.png]] | |||
17. Return back to the Object Pool (the section you were in at the beginning of this | |||
lesson - its the first symbol on the top left, 2 symbols back from the Segmentation | |||
Editor symbol) | |||
18. Right click on the label (now below the .raw file) and save the file. <b> Make sure | |||
to save the file as .RLE </b> | |||
[[Image:Amira-lung label13.png]] |
Revision as of 18:27, 2 April 2012
In order to evaluate changing densities in the lung of an affected animal, you need to
separate the lung portion of the CT scan from the rest of the CT scan. This is done by
creating a lung "label field". One method of generated a lung label is by a process
called "thoracic segmentation".
The idea is to color in sections of the lungs, using the ribs as a guide, and interpolate
the label between sections. This will generate a 3D segmentation of the lung which can
subsequently be analyzed for density values by histogram analysis.
1. Open the relevant .raw file
2. Adjust the parameters accordingly. For data from the MCPTI I use the following
parameters:
3. Then open the Segmentation Editor (see the cursor):
4. In the Segmentation Editor, open a New Label Data file (see the cursor), and the lung
CT data will load:
5. Add a New Material (see cursor, in this case Material2) so you can add label data to a
material file.
6. I like to adjust the Data Window to better show the CT data
7. Select the Paint tool so you can begin coloring in the lung label. I like to use a
point size of 60 to begin, and as I move on increase the size to 100.
8. Bring up the position of the CT scan towards the head (either scroll up/down over the
CT image or adjust the bar directly below the CT image). Position the image to show the
first set of ribs (see figure) and color in the area (shown in red in the figure, this
should take a single click of the mouse).
9. To clean up the image, hold down ctrl and click the mouse to delete label, use this
feature to exclude the region surrounding the spinal cord.
10. Scroll down approximately 3 ribs (watch the ribs emerge from the spinal cord area),
then color in this lung section. Delete the label surrounding the spinal cord (as shown
in the figure).
11. Next we want to interpolate the label that you made at the first set of ribs to the
label you just made at this 4th set of ribs. To do this go to Selection/Interpolate or
press ctrl-I. Scroll up and down to verify that the interpolation worked.
12. From the 4th set of ribs, go down another 3 sets. Color in this area (I like to use
paint brush size 100 from here on), remove spine label, and interpolate.
13. From this 7th set of ribs, go down until you see the diaphragm begin to appear. This
is located just below the heart. Color in this area, remove spine, and interpolate.
14. From the region of the diaphragm, scroll down until you don't see any lung left.
Color in this region as indicated, remove spine and interpolate. You don't want to color
the whole of this region because much of it is not lung, and you want to color it in in
the indicated shape so when it interpolates upwards it forms the desired shape.
15. The lung segmentation is now complete!
16. To save the label, add the label to the material (Material2) by clicking the + sign
(see cursor). Make sure you have Material2 highlighted, if you have nothing
highlighted, then the label you've just created will be lost.
17. Return back to the Object Pool (the section you were in at the beginning of this
lesson - its the first symbol on the top left, 2 symbols back from the Segmentation
Editor symbol)
18. Right click on the label (now below the .raw file) and save the file. Make sure
to save the file as .RLE