Computer Engineer
Email: glend at mail.nih.gov
Phone: 301-451-6236
Current and past projects:
Atlases, templates and spaces:
Latest AFNI atlas framework changes:
http://afni.nimh.nih.gov/sscc/staff/glend/README.atlas.html
Alignment across two sessions (special case):
http://afni.nimh.nih.gov/sscc/dglen/alignmentacross2sessions
Compiled AFNI Matlab applications:
http://afni.nimh.nih.gov/sscc/dglen/CompiledMatlab
Compiled Matlab programs for RETROICOR correction.
http://afni.nimh.nih.gov/sscc/dglen/McRetroTS
Anatomical to EPI registration: align_epi_anat.py script. The program uses the lpc algorithm described here:
http://dx.doi.org/10.1016/j.neuroimage.2008.09.037
and in HBM 2008 PDF here
http://afni.nimh.nih.gov/sscc/rwcox/abstracts/
The data below shows EPI data as it was acquired overlaid on top of the edge-detected anatomical data in colorized edges. On the right is the original data. On the left, the EPI data that has been aligned to match the anatomical data. Here alignment started off fairly close, but was improved by the alignment. Various visualization strategies can be used to assess alignment including the one shown below. In this case, the aligned EPI data follows the anatomical edges much more closely than before alignment. For visualization, the -AddEdge option to the align_epi_anat.py script produces images as produced in the NeuroImage paper link above.
Obliquity: How to deal with oblique datasets in AFNI. Dealing with Obliquity in AFNI
DTI-Query - DTI Tractography program by David Akers and Anthony Sherbondy at Stanford. Integration with AFNI. See http://afni.nimh.nih.gov/sscc/dglen/DTIQuery
Diffusion Tensor Imaging - developed non-linear model that allows for noise in the diffusion weighted images.
PDF presentation, April 19, 2005. Diffusion Tensor Estimation Method
Anisotropic smoothing technique. Rotationally invariant method. The 3danisosmooth program and method are described here
3danisosmooth PDF and in the Presentations folder.
Example below of DTI fiber tractography volumes rendered with AFNI from data processed with AFNI and DTIStudio.
http://afni.nimh.nih.gov/sscc/staff/glend/
