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Semiautomatic segmentation of the aorta with eVida Vascular
08 mayo 2017

Semiautomatic segmentation of the aorta with eVida Vascular

The software of advance visualization of images on 3D is designed for an optimal surgical planning of the aortic aneurysm

 

The segmentation of the aorta is one of the fundamental functionalities to consider in the endovascular planning software. eVidaVascular, designed for the surgical planning of the aortic aneurysm based on radiology studies of computed tomography (CT), involves a process of segmentation based on two easy steps that allow automating the process, that otherwise it should be done manually. All you need is to create a mask and indicate an area and a seed point.

The segmentation allows, by means of automatic algorithms, obtaining specific sketches of medical imaging that offer detailed information to the professionals. From an image, therefore, you obtain another images more representative of the structures that you want to analyze. The technique is one of the most used ones in the digital process of 3D medical images.

On the treatment of the aortic aneurysm, the segmentation of images is essential. The exact measure thanks to the 3D images, would make possible the election of the endoprosthesis (stent) suitable for the endovascular reparation (EVAR).

eVidaVascular makes possible this measure, so that the vascular surgeons and the interventionist radiologists can see, with the help of the software, that all the processes are insured and the risks are minimized on surgical operations. It is especially useful in the most urgent cases to treat.

 

Segmentation parameters

The algorithm of eVidaVascular take into account some parameters to identify the pixels of the radiological studies of the aorta and segment it automatically. The parameters are the following ones:

 

o   Level Min and Level Max: minimum value of density and maximum value of the aorta.

o   Neighbors: numbers of neighbouring points to take into consideration as a part of the aorta from the seed point that we mark.

o   Regular Light: It indicates if the study case has available uniform light or a regular one.

o   Preprocess: indicate if there can be an attempt to remove the bone and the soft nearby areas (kidneys, spleen, etc.)

The default values that the algorithm stabilizes would depend on the thickness of the cut of the case study.

Nevertheless, these values could be modified manually either before or after of realizing the segmentation of the aorta.

 

 

Segmenting the abdominal aorta (AAA), the thoracic aorta (TAA) and the abdominal and thoracic section (TAA)

  1. In each of the following cases, first of all it should be delimit manually the area of the radiologic study.
  2. After that, the plan would be move to the initial cut that you want to fix as the initial of the abdominal or thoracic aorta. And the same to establish the last cut, the end of the abdominal or thoracic aorta. Finally, the seed point would be mark, so that it would be useful as a starting point for the segmentation.
  3. Once you have done the previous steps correctly, the process of segmentation would be done automatically. The result could be revise in multi-planar reconstruction.
  4. If the segmentation offered is the correct one, a button would be press and the 3D planning would be open automatically. If the segmentation is not the correct one we can do the modifications that we consider.

 

Segmenting the iliac arteries (IA)

  1. First of all, it should be delimited manually the area of the radiologic study
  2. After that, the plan would be move to the initial cut that you want to fix as the initial of segmentation. If the endoprosthesis that is adequate to the study case is bifurcated, the beginning of the segmentation should be situated above the kidneys. If instead, the endoprosthesis is not bifurcated, the beginning of the segmentation could be in the aortic bifurcation. The last step would be repeated to delimit the last cut to take into consideration.
  3. Finally, a seed point would be mark, so that it would be useful as a starting point for the segmentation.
  4. Once you have done the previous steps correctly, the process of segmentation would be done automatically. The result could be revise in multi-planar reconstruction.

If the segmentation is the correct one, a button would be press and the 3D planning would be open. If the segmentation is not the correct one we can do modifications.

 

Over- segmented and under-segmented cases

In the cases that the offered segmentation is excessive as a result, the software offers a combination of tools for the retouch and adaptation (eraser tool, bin tool, etc.).

And when the segmentation offered by the algorithm doesn´t contain all the information that is needed, either because the contrast is not the adequate, because there is an excessive granulation or because the contrast hasn’t been dilute, the software makes also possible to eliminate the segmentation to do it manually or to add points of the areas that are not segmented.

 

You can download the free trial version of the software and verify by yourself all its possibilities.

 And if you have any doubt or we can help you in something, please do not hesitate to contact us.