FilterTracts[tracts,vox,{select.. }]

filters the tracts based on the list of select criteria. Select criteria are defined as {"logic",{"how", criteria}}. The "logic" parameter can be "and", "or" and "not". The "how" parameter can be:     - "x", "y", or "z" for slice selection, here criteria is a slice number     - "thourgh" for selecting tract that go through a roi, here criteria is a 3D mask.     - "within" for selecting tract that fit fully within the roi, here criteria is a 3D mask.     - "partwithin" for selecting the part of the tracts that fall within the roi, here criteria is a 3D mask. Any number of select criteria can be listed.