Dear SPM community
I want to extract grey matter volumes from an ROI for single subjects in Milliliters using marsbar.
The option “export data -> summary time courses for regions” in marsbar extracts a value which could be for example 0.464.
Is it corrects that multiplying this value with the volume of the ROI in Milliliters is the volume of the ROI?
I am using modulated warped grey matter data from the VBM8 toolbox.
I tried to test this extraction method, by using a different approach:
When I extract grey matter volume from the ROI with ImCalc, using a binary mask I get somewhat different volume values:
Volume = i1. * 12
i1 is the binary mask from the ROI
i2 is the modulated warped grey matter image (mwrp1)
The I used “get_totals” by Ged Ridgeway to calculate the volumes.
Why are the volumes different?
Many thanks for any hints
Best regards
Franz
|