Anry: /* Our Approach */

2012-11-21T17:42:34Z

Our Approach

Anry: Created page with '= Segmentation = Catheter ablation has been proposed for treatment of atrial ﬁbrillation arrhythmia. MRI data, obtained at University of Utah, are used to explore lesion ablat…'

2012-11-21T17:39:17Z

Created page with '= Segmentation = Catheter ablation has been proposed for treatment of atrial ﬁbrillation arrhythmia. MRI data, obtained at University of Utah, are used to explore lesion ablat…'

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= Segmentation =

Catheter ablation has been proposed for treatment of atrial ﬁbrillation arrhythmia. MRI
data, obtained at University of Utah, are used to explore lesion ablation and scariﬁcation
locations. In addition, MRI analysis may help to predict if the ablation procedure will help
a patient or not. Many of these image analysis tasks are largely based on segmentation of
left atrial wall, which is done manually or semi-automatically. Automatic segmentation uses
moving contours or surfaces (interfaces) to segment image data by minimizing a predeﬁned
energy function. These moving interfaces are highly aﬀected by image data, which can be
thought as a force ﬁeld pushing the interface to features of choice. Thus, the choice of
interface attracting image features is critical.

== Our Approach ==

We are exploring different image features that are appropriate for such automatic segmentation tasks.
Our objective is to develop and improve topological extrema ranking
algorithms (e.g., maximum persistence, and perceptual ridge importance) to provide the
most appropriate features, and to compare the results to expert’s manual segmentation.

Based on the obtained edge or ridge features, we are use two different approaches to create a contour.
The first uses a novel boundary linking algorithm where all the detected ridges converted to 8-point extrema vector,
and then the connections between ridges are made using these vectors. The second approach uses active contours to provide smoother results.

== Results ==

The example of extracted ridges is shown in the Figure 1. The connected boundary is shown in the Figure 2. For the tested volumes, when comparing the obtained boundary with expert's manual segmentation, the average distance error is about 2 pixels. The results of GVF active contour approach are shown in the Figures 3-5. The bright gray contour is the expert's segmentation, and yellow contour is the result of our algorithm. The average distance error there is less than 2 pixels.

<gallery>
Image:Ridge.png|Figure 1. Topologically important ridge structures
Image:Connected_ridge.png|Figure 2. Connected boundary
Image:Heart1topology.png|Figure 3. Frame 15.
Image:Heart2topology.png|Figure 4. Frame 17.
Image:Heart3topology.png|Figure 5. Frame 25.
</gallery>

== Project Week ==

[http://www.na-mic.org/Wiki/index.php/2012_Summer_Project_Week:RidgeExtractionAtrialWallSegmentation Summer Project Week 2012]

= Publications =

Nakhmani A., Tannenbaum A., "Automatic Segmentation of Left Atrium Wall Using Topologically Significant Edge Features," In preparation.

= Key Investigators =

* UAB: Arie Nakhmani and Allen Tannenbaum

@@ Line 18: / Line 18: @@
 most appropriate features, and to compare the results to expert’s manual segmentation.
-Based on the obtained edge or ridge features, we are use two different approaches to create a contour.
+Based on the obtained edge or ridge features, we are using two different approaches to create a contour.
 The first uses a novel boundary linking algorithm where all the detected ridges converted to 8-point extrema vector,
-and then the connections between ridges are made using these vectors. The second approach uses active contours to provide smoother results.
+and then the connections between the ridges are made using these vectors. The second approach uses active contours to provide smoother results.
 == Results ==

Projects:TopologicalSegmentation - Revision history

Anry: /* Our Approach */

Anry: Created page with '= Segmentation = Catheter ablation has been proposed for treatment of atrial ﬁbrillation arrhythmia. MRI data, obtained at University of Utah, are used to explore lesion ablat…'