VTA calculation

[jxm491Participant]

I was wondering if there was a way to simply generate VTA’s for subjects based on their programming parameters, or is it necessary to run through the actual image processing steps before doing so?

I have the electrode coordinates for each patient already, I am wondering if it is possible to extract the VTA’s and import them into subject space.

Thanks!

[andreashornKeymaster]

Hi there, you can create niftis with spheres at these sites maybe using FSL or other neuroimaging tools.
Then you can import them into the Lead-DBS viewer using the “Add Object” menu.
But in general, it’s not too easy to import things if you’re not really familiar of how Lead-DBS stores stuff etc.
Usually much easier to relocalize the electrodes quickly if you’re familiar with it.

Best, Andy

[jxm491Participant]

Thanks for the quick response Andy!

Are all VTA models spherical? Does the imaging characteristics come into play at all with the calculation? Or in general is the same for every subject.

I’m thinking that I will generate the VTA’s in MNI space for all subjects, extract the diameters and create the spheres using FSL. It would be nice to relocalize the electrodes, however I am not as familiar with that process.

[andreashornKeymaster]

No, depending on the model, they are not spherical and the local tissue properties are used to inform them.
For your purpose maybe the Mädler & Coenen model is helpful which gives you a diameter depending on Voltage and Impedance.

Mädler, B., & Coenen, V. A. (2012). Explaining Clinical Effects of Deep Brain Stimulation through Simplified Target-Specific Modeling of the Volume of Activated Tissue. AJNR American Journal of Neuroradiology. http://doi.org/10.3174/ajnr.A2906

Function that calculates the R is maedler12_eq3 inside ea_genvat_maedler

-> In case you want to get more familiar, why not have a look at this walkthrough video: http://www.lead-dbs.org/helpsupport/knowledge-base/walkthrough-videos
It’s not too complicated :)

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