11---
22layout : default
3- title : NFT
4- long_title : NFT
53parent : NFT
64grand_parent : Plugins
5+ render_with_liquid : false
6+
7+ title : Chapter-02-Head-Modeling-from-MR-Images
8+ long_title : Chapter-02-Head-Modeling-from-MR-Images
79---
810The steps of head modeling are segmentation, mesh generation, and
911co-registration of electrode locations with scalp surface. User may also
1012generate a source space to be used in the solution of the inverse
1113problem. Figure 2 shows the steps of head modeling using MR images.
1214
13- <center >
14-
1515![ Figure 2: steps of head modeling using MR images] ( NFM_Toolboox_UsersManual_html_2aaa1b22.gif )
1616
17- </center >
18-
1917Each step in realistic head modeling is implemented as a separate GUI
2018module reachable from the main menu. These modules are described in the
2119following sub-sections.
@@ -51,13 +49,9 @@ panel allows the user to select which image to display on the image
5149panels. The available choices are the MR volume, the filtered volume or
5250various stages of segmentation.
5351
54- <center >
55-
5652![ ] ( NFT_from_MRI_segmentation.png ) .....
5753![ Figure 3: Interface for segmentation] ( NFT_segmentation.png )
5854
59- </center >
60-
6155The panel on the right of the segmentation GUI shows the segmentation
6256steps that will be performed on the volume in order:
6357
@@ -111,15 +105,11 @@ watershed segmentation algorithm, and the default values work for most
111105images. The result of Brain segmentation can be seen by selecting “Brain
112106Mask”.
113107
114- <center >
115-
116108![ Figure 4: Interface of segmentation during setting lowest point
117109for cerebellum.] ( NFT_cerebellarlowpoint.png " wikilink ") ......
118110![ Figure 5: Interface of segmentation during a seed point
119111selection on WM.] ( NFT_WMpointselection.png " wikilink ")
120112
121- </center >
122-
123113### Outer skull segmentation
124114
125115For outer skull segmentation, seed points for the eye lobes are selected
@@ -130,17 +120,11 @@ click on both eye lobes. Figure 7 shows the matlab figure that pops-up
130120to click on eye lobes. Once the eyes are selected the outer skull is
131121segmented and can be seen by “Outer skull mask”.
132122
133- <center >
134-
135123![ Figure 6: Interface of segmentation to select an axial slice where the eyes are clearly observed.] ( NFT_eyeselection.png " wikilink ")
136124
137- </center >
138- <center >
139125
140126![ Figure 7: Matlab figure to click on eye lobes.] ( NFT_eyelobes.png " wikilink ")
141127
142- </center >
143-
144128### Inner skull segmentation
145129
146130Inner skull segmentation does not require any user input. After the
@@ -188,13 +172,10 @@ mesh file is suitable to be used directly by the BEM solver. The format
188172of the mesh file is given in [ Appendix A] ( /NFT_Appendix_A " wikilink ") .
189173The mesh generation process is described below.
190174
191- <center >
192-
193175![ ] ( NFT_from_MRI_mesh_gen.png " wikilink ") .....
194176![ Figure 8: Interface for mesh
195177generation.] ( NFT_meshgeneration_ui.png " wikilink ")
196178
197- </center >
198179
199180Mesh Generation module creates triangular meshes that fits the
200181boundaries of the segmentation. The aim is to approximate the geometry
@@ -246,13 +227,9 @@ A LFM using a regular grid source space can be used in single dipole
246227parametric inverse problem solution to find a coarse estimate of the
247228dipole position.
248229
249- <center >
250-
251230![ ] ( NFT_from_MRI_source_space.png " wikilink ") .....
252231![ Figure 9: Interface for source space generation.] ( NFT_sourcespacegen.png " wikilink ")
253232
254- </center >
255-
256233Co-registration of electrode locations
257234--------------------------------------
258235
@@ -287,12 +264,9 @@ the electrode positions change. Therefore, the co-registration output is
287264specific to a session. The result of electrode co-registration is saved
288265as Session_Name_Subject_Name_headsensors.sens in ASCII format.
289266
290- <center >
291-
292267![ ] ( NFT_from_MRI_coreg.png " wikilink ") ....
293268![ Figure 10: Interface for co-registration.] ( NFT_coregistration.png " wikilink ")
294269
295- </center >
296270
297271Head Modeling using Template Warping
298272------------------------------------
@@ -332,13 +306,9 @@ whole head model, and some electrodes may fall out of the template mesh.
332306
333307In Figure 11 the interface for warping module is shown.
334308
335- <center >
336-
337309![ ] ( NFT_from_Warping.png " wikilink ") .....
338310![ Figure 11: Interface warping of a template head model.] ( NFT_warping_ui.png " wikilink ")
339311
340- </center >
341-
342312------------------------------------------------------------------------
343313
344314References
0 commit comments