The device is formed from a multi-stranded micro-cable having a plurality of flexible strands of a shape memory material and at least one radiopaque strand. The strands can be made of a shape memory nickel titanium alloy, that is highly flexible at a temperature appropriate for introduction into the body via a catheter, and that after placement will take on the therapeutic shape. The radiopaque strand can have a core strand with a plurality of intermittently spaced apart enlarged radiopaque portions that may be a plurality of beads of radiopaque material spaced apart and mounted on the core strand, or a plurality of coils intermittently wound about and spaced apart on the core strand. A polyhedral occlusive device is also provided, adapted to be inserted into a portion of a vasculature for occluding a portion of the vasculature, for use in interventional therapy and vascular surgery.