Poster
# 40
Poster |
|
6th Internet World Congress for Biomedical Sciences |
Juan Gutierrez Aguado(1), Isaac Llorens i Eixea(2), Ricardo Ferris Castell(3)
(1)(2)Facultat de Fisica. Universitat de Valencia - Burjassot. Spain
(3)Universitat de Valencia - Burjasot. Spain
|
 |
|
|
|
[New Technology] |
[Medical Electronics & Engineering] |
[Radiology & Nuclear Medicine] |
Once an image coming from a MRI of XR is digitised, an initial contour must be estimated around the organ of interest. This task can be performed using thresholding, region growing, or some other methods that permits to obtaining it.
The energy is defined as in eq 1,
where the internal energy is eq 2:
, and the external energy is eq 3:
.
I(x,y) represents the grey values of the image. In this work, the option has been to use chamfer distance (5) as the external energy, which determines the distance between an image point and its nearest edge. This implies a previous step of determining the image gradient. Thus, an image can be obtained with high values far from edges decreasing gradually towards the edges. This provides information about the sense of diminishing of energy.
Representing v(s) by means of a cubic B-Spline, and rewriting the energy to take into account the digital nature of the images, it is possible to apply a greedy algorithm in order to minimize the energy. Thus, the initial contour will move to adapt itself to the contour of the object of interest, where the energy reaches its minimum value.
|
|
|
|
|
|
|
[New Technology] |
[Medical Electronics & Engineering] |
[Radiology & Nuclear Medicine] |
