OPT: enable to call function "extract_metric_within_tract" from other scripts without using method map
OPT: enable to call function "extract_metric_within_tract" from other scripts without using method map

3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox