[Freesurfer] Convert non-surface labels to volume masks

Dear Freesurfers,

I am trying to convert a non-surface label into a binary volume mask (does that make sense?).

To create the label I used tkmedit (brush tool) to select the voxels I need on the appropriate slices and saved as a label file. Then I tried to use mri_label2vol to convert this label to a binary volume mask by doing:

mri_label2vol --label lh-test.label --temp 100101AA/bold/006/f.nii --reg 100101AA/bold/register.dat --proj frac 0 1 .01 --subject AA --hemi lh --o 100101AA/bold/masks/lh-volmask.nii

I got an error: Loading ./lh-test.label ERROR: label ./lh-test.label is not a surface label.

So looks like mri_label2vol only works on surface labels. Is there a way to convert a label defined by tkmedit on the volume into a binary volume mask? Or is there a better way to do this?

Thank you.

Lingqiang Kong