PERF: std::map -> itksys::hash_map
PERF: std::map -> itksys::hash_map

thewtex/ITKUltrasound,KitwareMedical/ITKUltrasound,thewtex/ITKUltrasound,thewtex/ITKUltrasound,KitwareMedical/ITKUltrasound,KitwareMedical/ITKUltrasound