[Mristudio-users] Fwd: questions about ROI's

[Darren Gitelman]

I have several questions about ROIs

1) In both DTIstudio and ROIeditor ROIs of fixed size are placed with
reference to the lower right quadrant of the crosshairs. Is there a
reason for this or could the ROI be placed centered on the crosshairs?

2) I would like to know how dtistudio and roieditor calculate the
values of ROIs. Please see attached picture. On the left, is a 4 voxel
diameter circular ROI overlaid on a grid. This is what the ROI looks
like when I first draw it in either DTIstudio or ROIeditor. On top of
this is a set of brown voxels, which is what the ROI looks like in
ROIeditor when I add it to an object. On the right is the 4 voxel
circular ROI on top of a 4 voxel square. How do DTIstudio and
ROIeditor get the value of an ROI?
   - Does it perform a weighted average of voxels in the circle
(orange part of circle)?
   - Does it include only the voxels that show up in the brown object.?
   - Does it include any voxels that touch the circle (i.e., blue square)?

Do DTIstudio and ROIeditor do the same thing when determining the
value of ROI's?

3) Is there any way to un-associate an ROI from an object so that it
can be moved around again or once it's added to an object that's it?

4) Is there any way to save ROIs in DTIstudio?

5) I've noticed in ROIeditor that undo doesn't always undo the last operation.

Thanks,
Darren
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