<div>Hi Luis,</div><div><br></div>Hey I asked you earlier about the biplane image registration of 2D cerebral angiograms.<div>In that one option you suggested was to project the 2D images into a 3D volume and then track the minimum</div>
<div>values of that 3D volume.</div><div><br></div><div>Could you elaborate on this. How do I project the 2D angiograms into 3D volume in ITK?</div><div><br></div><div>Here the image set I have are two orthogonal views ( lateral and AP view) of cerebral angiograms. I need to get a 3D volume of the aneurysm specifically from both these 2D views. Means kinda register the two 2D views and align them perpendicularly. I hope this makes sense.</div>
<div><br></div><div><br></div><div>Eagerly awaiting your reply.</div><div><br></div><div>Anyone having ideas, would appreciate your help.</div><div><br></div><div>Thanks,</div><div>Gaurav.</div><div><br><div class="gmail_quote">
On Sat, Feb 13, 2010 at 3:50 PM, Luis Ibanez <span dir="ltr"><<a href="mailto:luis.ibanez@kitware.com">luis.ibanez@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi Gaurav,<br> </blockquote><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">This is a very interesting subject, that unfortunately<br>
doesn't have a straight-forward solution.<br>
<br>
Typically this is done by:<br>
<br>
<br>
A) Extracting centerlines from each<br>
one of the 2D projections.<br>
<br>
B) Finding bifurcation points (or in general critical<br>
points) on each view.<br>
<br>
C) Matching bifurcation (and/or critical points)<br>
between the views.<br>
<br>
<br>
The nature of the problem is such that you can't<br>
solve for all possible cases.<br>
<br>
Are the images acquired with a bi-plane Fluoroscopy<br>
system ?<br>
<br>
If so, at least you can build geometrical assumptions<br>
based on the fact that the images will be aligned in<br>
the circle of rotation of the Fluoroscopy machine.<br>
<br>
--<br>
<br>
You may want to take a look at the application:<br>
<br>
Curves2DExtractor<br>
<br>
in InsightApplications<br>
<br>
<a href="http://www.itk.org/ITK/applications/Curve2DExtraction.html" target="_blank">http://www.itk.org/ITK/applications/Curve2DExtraction.html</a><br>
<br>
This application was developed to detect centerlines<br>
in 3D Angiograms, in a context related to brain aneurysms.<br>
<br>
You could use the resulting centerline points as the input<br>
for a process that finds geometrical correspondences.<br>
<br>
<br>
---<br>
<br>
Another independent approach, is to project both of the<br>
2D images into a 3D volume, and then track the minimum<br>
values of that 3D volume. This of course is far from being<br>
free of ambiguities, but at least it should give you an easy<br>
initialization for correspondences between the thick vessels<br>
at the base of the skull.<br>
<br>
<br>
<br>
Regards,<br>
<br>
<br>
Luis<br>
<br>
<br>
---------------------------------------------------------------------<br>
On Fri, Feb 12, 2010 at 10:21 PM, Gaurav Sharda<br>
<div class="im"><<a href="mailto:gaurav.sharda.uiowa@gmail.com">gaurav.sharda.uiowa@gmail.com</a>> wrote:<br>
</div><div><div></div><div class="h5">> Hi there!<br>
><br>
> I am Gaurav Sharda, a graduate student in University of Iowa,US.<br>
><br>
> I am going to start my work on cerebral aneurysm Angiogram Registration.<br>
> I am going to have 2D angiograms of side view and top view of brain. Could<br>
> you suggest some registration techniques to find the co inciding portions?<br>
> The images are roughly orthogonal.<br>
> Please see if you could suggest some techniques and give me some useful<br>
> links.<br>
> Thanks a lot..<br>
><br>
> Gaurav<br>
><br>
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