[FieldTrip] tissue labels in mesh for prepare head model

RICHARDS, JOHN RICHARDS at mailbox.sc.edu
Mon Jul 11 04:14:41 CEST 2016


I switched a couple of months ago to a version of FT.  I am using simbio meshes and ft_prepare_headmodel for a FEM source analysis.

This is the code to prepare the mesh:  (mri.tissuelabel is in the mri structure).
cfg        = [];
cfg.shift  = 0.3;
cfg.method = 'hexahedral';
cfg.tissue = mri.tissuelabel;
mesh = ft_prepare_mesh(cfg,mri);

This results in a struct with
hex
labels
tissue
tissuelabel

When I run 
cfg        = [];
cfg.method ='simbio';
cfg.conductivity=conductivity1;
vol        = ft_prepare_headmodel(cfg, mesh);    

I get several instances warnings (see below).  The warnings are because the getdimord does not recognize “labels” and “tissue”.  But the ft_headmodel_simbio needs the tissue to tell which tissues to assign conductivity to a hex voxel.  See header of the ft_headmodel_simbio, designates hex, tissue, and tissuelabel.  

This used to work in the previous version; it may still be working just giving a warning.

Any help?

John

E.g., from header
Use as
    headmodel = ft_headmodel_simbio(mesh,'conductivity', conductivities, ...)
 
  The mesh is given as a volumetric mesh, using ft_datatype_parcellation
    mesh.pos = vertex positions
    mesh.tet/mesh.hex = list of volume elements
    mesh.tissue = tissue assignment for elements
    mesh.tissuelabel = labels correspondig to tissues
 
  Required input arguments should be specified in key-value pairs and have

Warning: could not determine dimord of "tissue" in the following data 
> In getdimord (line 549)
  In ft_datatype_source (line 232)
  In ft_datatype_parcellation (line 178)
  In ft_headmodel_simbio (line 46)
  In ft_prepare_headmodel (line 430)
  In CreateFieldtripHeadModels (line 348) 
            hex: [1440558x8 double]
         labels: [1440558x1 double]
         tissue: [1440558x1 double]
    tissuelabel: {'wm'  'gm'  't2wcsf'  'dura'  'skull'  'scalp'  'head'  'eyes'  'nasalcavity'  'nma_pve'}
           unit: 'mm'
            cfg: [1x1 struct]
            pos: [1487661x3 double]
         inside: [1487661x1 logical]

AND

Warning: could not determine dimord of "labels" in the following data 
> In getdimord (line 549)
  In ft_datatype_source (line 232)
  In ft_datatype_parcellation (line 178)
  In ft_headmodel_simbio (line 46)
  In ft_prepare_headmodel (line 430)
  In CreateFieldtripHeadModels (line 348) 
            hex: [1440558x8 double]
         labels: [1440558x1 double]
         tissue: [1440558x1 double]
    tissuelabel: {'wm'  'gm'  't2wcsf'  'dura'  'skull'  'scalp'  'head'  'eyes'  'nasalcavity'  'nma_pve'}
           unit: 'mm'
            cfg: [1x1 struct]
            pos: [1487661x3 double]
         inside: [1487661x1 logical]

***********************************************
John E. Richards Carolina Distinguished Professor
Department of Psychology
University of South Carolina
Columbia, SC  29208
Dept Phone: 803 777 2079
Fax: 803 777 9558
HTTP: jerlab.psych.sc.edu
***********************************************







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