<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hi all, </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
I have two questions about some eField models that I've created: </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
1) Is there a simple way to extract the measured scalp-to-cortex distance between the defined TMS position and the cortex? I imagine SIMNIBs must calculate this in creating the eField. I would be very interested in extracting that information for other analyses. </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
2) In interpolating my electric field models to .nii files, I'm attempting to discern how best to threshold the eFields such that I might create a Region of Interest of mask based on the precise site of stimulation. I know that there is much debate surrounding
1 V/m as a critical value in tDCS modeling. In TMS, I've noticed that even in my modeling of stimulation intensities that are particularly low (40% MSO, 58.4 dI/dT on Magventure), the resulting eField has a rough value of about 45 V/m at the site of stimulation
(crosshairs at the first image), but even areas near the occipital cortex have a rough value of 3-4 V/m (crosshairs at second image). While proportionally this V/m is much smaller than the actual site of stimulation, I could imagine one might argue that a
value of 3-4V/m may influence cortical neurons.<br>
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Is this a typical result or is it possible I've made some critical mistake in my modeling?</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Thank you so much for your help!</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Best,</div>
<div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div id="Signature">
<div>
<div style="font-family:Tahoma; font-size:13px">Dan McCalley
<div>Medical University of South Carolina</div>
<div>College of Graduate Studies, Neuroscience</div>
<div><br>
</div>
</div>
</div>
</div>
</div>
</body>
</html>